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I'm the second owner of my pretty much stock 03 Pathfinder SE (auto, part-time 4wd) since 2015. Things happened in 2020. Decided to convert the Pathfinder to manual. Bought a manual trans from a 2002, took my time, and in summer 2023 finished rebuilding it. Not including that here as it's pretty routine - all new synchros, bearings, input shaft and some gears that had chipped teeth, then back together. If you have a 2000, 01 or 02 part-time or rwd you can swap in a manual, get a manual ECU, (deal with NATS), and be done. (You can't manual swap a full-time 4wd, fulltime unit only works with an auto) My problem with the 03 was Nissan discontinued manuals in the US in late 2002 for model year 2003, which also had new revisions with a more advanced ECU including electric throttle body and other changes. So I could either go 'backwards' to a US 2002 manual ECU and install throttle cable, find a wrecked US manual truck and swap everything across - or get an 03 manual ECU and make it work. I didn't want to go backwards. I'm also in WA which doesn't do smog checks so no issues modifying or mixing and matching. Luckily, Nissan still sold the 03-04 as manual in Canada. Looking at parts diagrams in Amayama it looked like the Canadian auto 03 model was near-identical to the US model, so the manual couldn't be that different, I figured. The worst outcome was it wouldn't work at all, or that I'd have to keep spending money until it worked or I gave up. I took the gamble. I reviewed the earlier Pathfinder auto to manual guide linked on this forum, and also looked up a lot of 350Z conversion forums as it's the same engine and ECU. Also Nissan Skyline and 300ZX forums as different engine, but same transmission. I found the throttle body changed part numbers in 07/2002 from cable to electric, so that was the cutover date. Anything after that was right. I searched individual junk yards in Canada until I found a place selling a clutch pedal and bracket, ECU, and flywheel. The tell with the 'right' car was there were no throttle/cruise cables in the engine bay pics, cuz electric throttle. The yards that had what I needed were in rural Alberta. Apparently Alberta has a lot of R50 Pathfinders in their yards. I mainly used car-part.com. I sent the ECU away to get NATS disabled so I wouldn't need to deal with it. Got everything in and worked end of summer 2024, and wanted to share here. Pics and posts to follow once I get an image service set up.

He has been an NPORA member for nearly 20 years and a regular the whole time. Recently he worked with us in the background to get the forum back online, root out problematic DDoS sources and test for reliability. And now adamzan has agreed to join the Mod Team. Welcome adamzan!

I have not yet been given an actual cause for this nearly week long outage, but after spending hours on the phone with the host company today, repeatedly reminding them that they had assured the site would be back up before this past weekend, here we are back up and running... finally! edit: Turns out the host utilizes AWS facilities, so this was related to the major AWS outage that occurred at the same time. Don't know why they couldn't just say that from the beginning.

First things first - remove the transfer case Lots of extensions needed to get to bellhousing bolts. I bought proper long ones after this. Auto transmission detached Flexplate Flexplate removed Source of my rear engine oil leak (after clean up) - rear pan seal job was badly done Sealed it up good. Also I didn't take a photo, but you need to remove the steel inner collar. It's a total pita to get out. It centers the torque converter, but the manual transmission uses a small brass one. There's videos online, the 350Z auto to manual conversion videos cover it. I couldn't get it out for hours and broke various tools, I thought that was the end of the project. But I got it out eventually with the exact right sized puller. Fortunately the R50 chassis has the clutch master cylinder hole already there under a plate Turns out the auto trans computer sits on the other side of the clutch blank plate so both come out at once Factory clutch master cylinder. I thought about steel clutch lines, but ended up using an ebay 240SX clutch line kit. Works fine.

Pulled it out to give it a wash today.

Good day everyone, one morning I was on market place and found a VG33ER forsale for a decent price and for a and was a good few hours drive but I picked it up with no prior intention of swapping my pathfinder. The swap is pretty straightforward along as you have all the parts from an ER to swap. It is also 02 Xterra ECU swapped on the original body and engine harness. The pulley is swapped now as of writing to the 4x4parts 2.4 quick change pulley on the stock SCB cut off. It makes a significantly more amount of power than before and is absolutely worth it if you can afford the premium gas. ALTHOUGH, it seems the MPG has been improved since the swap at least at partial throttle which is pretty cool. It's also running factoy R50 airbox with all original sensors. Here's what was swapped Lower intake Injectors Fuel rails (minor differences) Supercharger Spark plugs Spark plug wires Thermostat 180 to 170 AC tensioner only NOT alternator Belts Crank pulley Water and ps pulley NOT alt ECU and plug Pas side valve cover (only for PCV valve) To swap the ECU most of the pins are in the same locations how ever not all. you WILL have to solder a larger pin on the orange IACV wire and to make the SCB safety work you can reuse and replumb the map/baro switch as the SCB and it works the same. All valves, sensors and anything else are original 97 pathfinder. You will have to run different length belts for all 3 now that the V belt is deleted, the crank and water pump are different size and the super charger belt needs to be a 5 rib and shorter unless you swap the AC comp. Cruise even works too! It drives incredible and I could not be more happy with the result. before the pulley it feels like a more peppy VQ but after the pulley it pulls harder than one for sure. When I dump the clutch I'm always first off the line even to the diesel guys that book it off the light (i'm looking at you Dodge owners) and it seems to run cooler than my friends bone stock X since mine has a hole in the hood and gets good cooling. Thanks. Donor engine in back of my r50 On floor after getting it home repinning the ECU plugs Cleaning Radiator shows up Installing charger and intake *borart voice* VERY NICEEE

Rock auto has reman and some new off brand ones that are decent just don't get the cheapest of cheap sometimes those aren't that great. GB stuff is pretty good from what I've heard never tried it personally though Also, you only need 1 post you don't need to add to multiple sections of the forum

Just incase anyone needed to know, you CAN fit a fully dressed VG33ER in the back of an R50!

Here's a link to the service manual. Page 196. basically warm, then hold no load 2k rpm for 2 minutes then check timing in N should be about 15 degrees +/- 2

I have an extra distributor that I marked core. I have had it so long I forget why I marked it that way. I figured I would try and put that one in and see if the issue goes away. The issue went away. I couldn’t get it any closer than 17 degrees. That’s within the range the manual gives. I am relieved to know that it should be the distributor. I will get an another one and cross my fingers that it fixes the problem. I will report back after the new one is installed.

The manual transmission chassis cover plate was unavailable, so I cut the existing one to fit the manual shifter The service manual says to fill the transmission from the shifter hole, so I did Intermediate covers and soundproofing Manual transmission trim installed The original auto transmission connector block. I connected up the neutral position switch to the PNP relay so it only starts when the shifter is in neutral. And connected up the reverse lights, just four wires

I made an adapter for my transmission jack to securely hold the manual transmission in place. I've used ordinary jacks to reinstall car transmissions before but this thing is pretty heavy even without the transfer case and I didn't want it falling on me About to go in Lining up manual transmissions just right to install is always annoying. Sometimes you gotta take it completely back out and down and start again. Sometimes it pops right in You can see the innards of the transmission before the transfer case is attached. Without sealant the transmission oil would all seep out Technically the manual transmission transfer case is different - it has a small gutter under the input shaft, and subgears to absorb shock. But nothing that is needed for the conversion. The auto transmission transfer case works fine. But you have to apply sealant as the back of the manual transmission is open

A pic of the back of the new flywheel showing 03-04 signal plate A view of the clutch fork from the outside. It pushes towards the engine, which pulls the pressure plate 'off' the clutch and flywheel

So first I tried a 350Z flywheel - but it was too high and wouldn't allow the pull clutch to work so couldn't release the clutch. So pulled the transmission out again, and next I installed a US '02 flywheel But the signal plate is way different, it's for the cable throttle ECU and the engine wouldn't start 00-01-02 signal plate on left with like 300 or something holes. 03-04 signal plate on the right. The right side has 3x 10 holes. That's what I needed, but flywheel not flex plate I found I needed part number 123105W90A (03-04 only) which is unique to the R50 Pathy due to the pull clutch. It was hard to find but found one in the UAE from I think partsouq Correct flywheel installed I found the starter motor had to be shimmed back about a 1/2 inch otherwise starter gear would hit the flywheel. There's an official part number for this, a plate the starter sits sandwiched under, but it's out of stock so I just used washers OEM clutch plate is an Exedy Pressure plate installed It's pretty big as pressure plates go, but the pull clutch means the clutch pedal is light (is why they chose it for the Pathfinder - more grab but lighter to use)

Clutch pedal installed. I couldn't find a Pathy brake pedal - probably because its bracket wraps around the steering column. I kept hitting the brake when I went for the clutch, so I ended up just cutting the brake pedal the same size as the clutch pedal and it looks factory now You can't really see, but the clutch pedal bracket goes where the auto trans computer used to be. It has a clutch starter switch but I didn't connect it (did connect the neutral start switch though) The Pathfinder manual uses a pull clutch (not a regular push clutch) which I had to figure out how it works Got the OEM parts Assembled. It 'clicks' into the pressure plate on installation. Then to release you pull out that pin, and the fork falls out. You lift the collar on the clutch release bearing to release it from the pressure plate. It's kinda hard to explain without seeing it in action.

I had never rebuilt a manual trans before. Followed the service manual, "Beer Garage" (since deleted), and youtube videos and took my time. I used a toaster oven to make dropping the press fit gears back on easier. I bought a factory shifter. But I thought it was too tall so I cut about an inch off it and welded. I am not a professional welder at all. But it has held up fine. I also found and bought a NOS Pathfinder clutch, and a 350Z flywheel. I figured a 350Z is the same engine and clutch, and the clutch and flywheel fit together. Seemed so far so good.

My one tip is to make sure you can get the fill plug loose before draining the oil.

I'm running a Magnefine on mine as well. I don't know that it's strictly necessary, but I wanted to give my high-mileage slushbox every chance I could, especially after seeing a little glitter in the fluid when I flushed it. I routed the lines on mine so the fluid goes from the trans, through the stock cooler in the rad, through the aux cooler, through the filter, then back to the trans. My thinking was that the OE cooler can only bring the fluid temp down to the coolant temp, so it should be the first stage. I put the filter on the return side just in case the cooler (which was not new when I installed it) had some schmutz in it. That I don't know. But I've had the filter on mine for the last 30k miles, and it hasn't complained.

Finally got this engine built New pistons, Rings, Bearings, Timing Chain, guides, tensioner, Water pump, clutch, plugs, leads, oil pump First Start on Thursday, Yesterday I took it around the block, got a heat cycle through it then retorqued the head, set valve clearances and dialled the timing in. It sounds and feels great! Ready for the next 500,000 hopefully!!

well got it all on the ground yesterday and drove it around. gotta get the alignment done, new tierods, rack bushings and possibly another set of camber bolts. I have everything in the garage but just ran out of time. Also front diff isnt in since pinion seal is trashed and i think its leaking behind the passenger axle. may just source another diff from the junk yard. Otherwise it drives around! just got to get these AC coils and 9446s to settle in and well be good! https://imgur.com/3XhUaw5 https://imgur.com/6QKYQiV

I know a lot of people like to delete stuff like those lines but the truck just runs better when you don't try to engineer it yourself lol.

so little update. Got my SFD ordered back in like november and it showed up in december BUTTTTT the lovely people at UPS messed up the box quantity with item quantity and the tariffs/duties skyrocketed to 2400 bucks per box. which means 4800 for 2 boxes with 500bucks worth of parts in them lol so its been re routed back to the shipper in canada and is currently "lost" per ups but they found it in montana. It has been an absolute shyt fest and waiting. So in the meantime i put on some 2in AC coils from 4x4parts and debating on if i want to rip the trans out of it to do the clutch now and replace the input shaft bearing since it is howling and making all kinds of racket. Heres a pic of the truck last night after i did the coils

yep ! that's a good guy ! happy that the forum is back online... facebook groups are just not my thing when you search things ! way to go adam

Thanks! Glad to help out.

Not able to upload photos with insert image 2" AC coils with 4" SFD, kyb struts, missing link, LR RKB101060.C8 about 6 inch rear lift, Bilstein 5125 33-185569, Warn Hubs, -3.75 backspacing, 33x12.5R15 Duratrac Wrangler, tire carrier with full size spare https://imgur.com/gallery/AIvp4br

Okay, so I figured out why I was having such an issue. It was the wrong seal. Sigh.

Well (expletive.) Thank you for the info. I have been turning wrenches for maaaany years and my brain did not put those two together. Totally makes sense. Thank you for knocking the cobwebs off of this old head. Checking out HPS now.... WOW. How have I not found this before. Thank you dudes!!! I owe you both a FEW beers....

Alright, got it through emissions and re-registered! Only 8 months late... Last night I installed a non-fouler on the downstream driver's O2 sensor and it seemed to do the trick. Not only did the P0430 not move to stored to screw up my day, but it's also no longer in pending. Steering was a little more squirrelly today. I need to get to the bottom of that. But otherwise, the truck is operational. Hoping to do a shakedown run soon.

https://hpsperformanceproducts.com/ Not the cheapest thing, but I intended to never have to deal with it again Silicone is fine for vacuum lines and coolant lines (reinforced in the latter case for the pressures) but also worth noting can be more difficult to seal at the ends (hence I use coolant-exposure-rated RTV for added insurance). It's true different kinds of rubber - of which at this point there's so many I've lost track - are good for different kinds of things and will fail if mis-applied. Here's my cheat sheet: For fuel hoses, I replaced everything with Gates Barricade except for the submerged hose in the tank/pump which was some super special snowflake stuff (fuel submersible rated) - and wildly expensive. Crankcase ventilation/PCV - Gates PCV/EEC Vacuum/Coolant - (reinforced) silicone as noted

Look for a manual car wash, the kind that eats quarters and gives you time with the spray wand. Don't shoot it directly at electrical connectors or fluid caps if you can avoid it, otherwise give 'er hell. I'd spray it down before you get in there. It's much nicer working on something that isn't an oily mess.

Haven't dealt with this on my Pathfinder fortunately, but did on my 98 Frontier. It sucked. Charcoal pellets all the way from the rear of the truck to the solenoid valve in the engine bay. My issue produced a P1444 (purge solenoid valve) but the codes in that series tend to be related, and in my case the code was brought about by a ruptured charcoal canister. Blowing and vacuuming the lines is not enough. The charcoal crumbs get jammed together in the lines. You need to use a stiff, but flexible, wire to push through every hard line, and it may be necessary to remove any hoses. Flush the lines with pressured water if possible, but house pressure is fine. Then continue to blow and vacuum the lines using whatever attachments you can to maximize pressure. Repeat this couple times. Any little charcoal crumb will eventually clog the line or find its way into the solenoid. My long term solution there was to put a transparent fuel filter on the line right off the canister. BTW, the solenoids can be fixed if they clog, since they're not cheap to replace. You just bend the little metal tabs in a little and split the coil portion from the plunger. Some pins/needles can dislodge pieces that are blocking the valve. The solenoids are also commonly used on other Nissans (the one on my 04 Pathfinder is identical to the one on my 98 Frontier). Not sure about the "405". What are you using to pull codes? Is the code exactly "P0405" on screen? Reason for asking is because in 98, you could pull "codes" directly from the ECU without a scanner, but the code it flashed was not the DTC "P" code. The FSM was needed to convert the ECU code to the DTC code. I'm not seeing "0405" as an ECU nor DTC code in the 98 R50 FSM, so that's why I'm curious about what's being used to pull the code. Maybe it's P0450 (control system pressure sensor) and there's a leak if a hose was disconnected or misrouted?

Thank you! haha. It's been a treat for sure. I was going to do a write up style post but didn't feel I had enough pictures to go with the information.

im using stainless hex bolts that are way too long compared to original. my OG hardware was actually studs and nuts on the R50. They're the same through all 80-00 Nissan 4x4s from what I can see. my friends Xterra, brothers wd21 and my r50 all share same hub hardware

Look for vacuum leaks, and check the tube from the throttle body to the airbox.

lo tendre en cuenta bro gracias

Hopefully yours don't look like that! A couple did in the VG33 I was going to put in mine, and some of the missing material had found its way past the pickup screen and chewed up the oil pump. The crank and cam bearings were all shot, I assume from low oil pressure. It still ran surprisingly well.

First Commute to work today, (A.K.A. real test. 70km each way) and the little Z sounds and feels happy

Twelve years of owning an R50, and almost 28 years owning and working on Nissan trucks (and cars, briefly)...and I'm just now getting around to putting together something like this. Still seems like people are trying to keep these trucks on the road, so hopefully this helps. This is a current matrix of maintenance and service parts for the R200A and H233B axles/differentials found in R50 Pathfinders and JR50 QX4. It covers all basic parts like seals and bearings, providing the current Nissan part number, superseded part numbers, quantity used, and a few suitable aftermarket part numbers. It also indicates which parts are No Longer Available ("NLA") from Nissan; they might still be available from international brokers and suppliers like Amayama.com and Partsouq.com. This list (particularly the aftermarket part numbers) is not comprehensive, but should be a good starting point; nearly all of the parts listed have a confirmed cross-reference to the OE part, some I've personally used. RockAuto's part number search DOES search across interchange numbers listed on parts; enter the OE part number without hyphens (i.e., "3818921G17"). There are definitely other parts that will work, especially more-affordable options; compare the specs of a listed part to other parts. It does not include any differential parts, LSD parts, or parts that would be needed to set up gears like shims and spacers...the majority of those parts are completely unavailable. The best option if wanting to change gears is to source a complete 3rd member or entire front differential from a donor vehicle, and service it using the parts from this matrix. Due to the nature of the high-pinion R200A we have, there are NO aftermarket gears available for it. Again, this is SPECIFICALLY for R50 trucks only. Other R200A front differentials (like those from W/D21, W/D22) do use some of these parts, but not all. The H233B data is for 33-spline only. Again, some parts do interchange, but some do not (mainly the inner seals and outer bearings which are sized smaller for 31-spline shafts). Keep in mind replacing many of these parts requires access to specialty tools, like pullers and a floor press, to disassemble and/or assemble components. Most of these parts cannot be bashed off, and some rental tools at your local auto parts store may be insufficient. A clamshell-style bearing puller like this works great for pulling pinion and carrier bearings. The matrix likely applies to foreign Terrano and Regulus models, too, but do your homework because you know Nissan did some really dumb things with these trucks. Part R200A (R50 Pathfinder ONLY) H233B (33-Spline ONLY) ! Qty OE Part # Supersedes NLA Aftermarket Part # ! Qty OE Part # Supersedes NLA Aftermarket Part # Pinion Nut 1 38216-U301A 38216-U3000 1 43262-50A0A 43262-50A02 Pinion Seal 1 38189-21G17 38189-21G15 38189-21G16 Y SKF: 15882 National: 710591 Timken: 2011S 1 38189-C7123 38189-C7021 38189-C7023 SKF: 16468 Schaeffler: SS2722 National: 710245 Timken: 710245 WJB/InMotion: WS710245 Outer Pinion Bearing 1 38120-1320A 38120-13201 Timken: 32306 WJB/InMotion: WT32306C SKF: BR32306 1 38120-1320A 38120-13201 Timken: 32306 WJB/InMotion: WT32306C SKF: BR32306 Inner Pinion Bearing 1 38120-61000 National: 32307 SKF: BR32307 Timken: 32307 1 38120-76500 38120-7650A National: 32308C SKF: BR32308 Outer Shaft Seal (LH) 1 38342-N3100 38342-P9000 SKF: 550231 Beck/Arnley: 0523506 Timken: 223542 National: 711070 A 2 43232-42G10 43232-42G00 National: 710176 Beck/Arnley: 0523492 SKF: 22120 Timken: 710176 Outer Shaft Seal (RH) B 1 40227-31G00 National: 710398 SKF: 19689 Schaeffler: SS3016 Axle Shaft Bearing (LH) Not Applicable 2 43210-0W000 SKF: GRW190 Mevotech: H516005 Beck/Arnley: 0514115 BCA: WE60346 National: 516005 Schaeffler: 101836 GMB: 7500024 Axle Shaft Bearing (RH) B 1 43215-H5000 43215-22500 43125-H5000 Y WJB/InMotion: WBRW114R Timken: RW114R National: RW114R Duralast: RW114R Axle Shaft Bearing Collar (RH) 1 43255-H1000 43255-18000 Y Not Applicable Inner Shaft Seal (LH) Not Applicable C 2 43252-0W000 Timken: 710479 National: 710479 Beck/Arnley: 0523727 SKF: 14782 Centric: 417.42011 Inner Shaft Seal (RH) 1 43252-H1000 SKF: 550232 Timken: 1181 Carrier Bearings 2 38440-N3111 National: 30209C Timken: 30209C BCA: NB30209C 2 38440-60000 Y National: KC11445Y SKF: KC11445Y Timken: KC11445Y WJB/InMotion: WTKC11445Y Differential Gasket D 1 38320-21W00 38440-N3110 38440-N3100 Y NONE - See Notes 1 38320-T3322 38320-T3321 38320-T3320AS 38320-T3320 O-Ring - Side Shaft Bolt (LH) 1 38223-21000 33125-Z5002 Not Applicable O-Ring - Outer Axle Tube Not Applicable C 2 43085-42G00 Beck/Arnley: 052-3568 SKF: 42G00 Fill Plug 1 00931-2121A 00931-21210 00931-21200 1 00931-2121A 00931-21210 00931-21200 Drain Plug 1 32103-U840A 32103-U8401 1 32103-U840A 32103-U8401 JPG version ! INSTALLATION NOTES A Axle shafts must be COMPLETELY disassembled (ABS tone ring, bearings, bearing cup, etc.) in order to replace the outer axle seals. This process requires a suitable tool and/or press. These seals are mainly grease-catchers for the bearings. However, if the inner seal is leaking gear oil, it likely has compromised the bearing grease. Axle shaft tear-down is recommended to regrease the wheel bearings and replace the seals. B Replace the RH outer shaft seal, outer bearing, and bearing collar together. The bearing shaft collar MUST be destroyed-off with a cold chisel BEFORE the bearing can be removed, and before the seal can be replaced. Attempting to pull the side shaft with the collar installed WILL destroy the flange plate (38232-01W00) and bolts. Ask me how I know. The "RW114R" kits all include a bearing and new bearing collar; the seal is sold separately. A slide hammer is needed to pull the shaft from the bearing, and a press is required to install the bearing and bearing collar on the shaft. C The axle shafts must be completely removed from the axle in order to replace the inner shaft seals and outer o-rings located at the ends of the axle tubes. This requires disconnecting the parking brake and hydraulic brake lines from the drums. The axle shafts will rest on seals, and potentially damage them, when the axles shafts are only partially pulled from the differential. FSM says to remove the ABS sensors from the axle tube to avoid damaging them when pulling the axle shafts. D The R50 Pathfinder uses a 9-bolt R200A differential only found in E50 and E51 platforms. All other R200A, R200, and C200 differentials found in other Nissan trucks and cars have 8-bolt covers. There are NO aftermarket gasket options for the 9-bolt differential.

Thank you so much for taking the time to not only research, but explain it in a way that isn't complicated! I'll report back once I am able to put your words into action. I just wanted you to know your kindness is greatly appreciated.

Well, tore it down and put it back together with a new pump. The "new" one I put in was leaking pretty bad, guess the seal was bad from the get go. All is well now. Thank you for all the input gents!

I've heard of the dampers causing bleeding issues. I don't think I've heard of one doing what yours is doing, but it does sound plausible. If nothing else jumps out at you, look for an M10x1 invert flare (not bubble) union. And yeah, I'd check under the dash first, if only because I hate bleeding hydraulic systems.

i bought these same ones years back. Hit the tip of that center section with a flapper wheel and knocked it back a little. used the stock cclip and all was well

You have power at the key itself, or at the switch? What are you checking at the column? Do you mean you've got no dash lights, or are the dome and headlights out too? I would check your work with the alarm system removal. If the ignition switch has come unplugged, or a connection to or from it has failed, that could explain a lot. I am assuming you've already checked the battery terminals.

My parts hoard has saved me several times lately. Torsion bars for my Xterra, one let go. Found I had a nearly new oem set I bought off of a guy 15 years ago who fitted aftermarket bars on his. Perfect, free repair! Fan clutch went on the X, ripped the one off my old 94 wd21 that wasn't that old, it looked the same so I put it on.

Ha, I just did this the other week to pass emissions (it worked). But, a few things to know: I started with Dorman 42109. They're like a mile long and comically shiny for something you don't want to be visible, depending on where you are and how emissions are done (no concern for you since WA doesn't do emissions). However, the length is fine for the driver's side, but on the passenger side it'd be a tight fit because the sensor will be up against the transmission. I ended up not even opening the package and returned them. I used Dorman 42009, which are shorter and also a little on the shiny side. However, these need to be drilled out sufficiently to clear the sensor tip... Lastly, and perhaps the most important part: keep in mind these are sold as "spark plug de-foulers/non-foulers" and are not meant for O2 sensors. In my case, I realized that the O2 sensor on my passenger side has a tip that much larger than the sensor on my driver side. So even after drilling them out, it would not fit on the passenger side without compromising the threads of the adapter. If you go this direction and the O2 sensor tip is too big, this approach likely won't work. A 90° might be okay and clear the passenger side.

Howdy. If you're not familiar with the Factory Service Manual, they can be extremely helpful: https://www.nicoclub.com/nissan-service-manuals. Recommend to download each PDF for your model year (there's a download link below the inset PDF viewer). The General Information (GI) is a great starting point for how to read diagrams, wire colors, harnesses, etc. You'll want the Automatic Transmission (AT) chapter for the P0740: https://www.nicoclub.com/service-manual?fsm=Pathfinder%2F2002%2Fat.pdf You'll want the Engine Control (EC) chapter for the others: https://www.nicoclub.com/service-manual?fsm=Pathfinder%2F2002%2Fec.pdf For the P0740, ignore the "Starter Signal Circuit" part of what your code scanner is giving. The code is for the torque converter clutch signal. You won't notice anything different for gears 1-3, as this applies to the transmission being able to lock up the torque converter while in 4th gear after the transmission has warmed up. Either the valve's not functioning, or the circuit from the transmission control module (TCM) to the solenoid is open. Lowest hanging fruit is checking the harness under the truck on the passenger side; should be a small heat shield to remove and also checking one of the wires for ground continuity. The solenoid requires some work to access from underneath the transmission with the pan off, so taking it to a shop depends on much you're willing to take apart. P0420 and P0430 are the same codes, one for each side/bank of the engine. It's unlikely that sensors on both sides and/or catalytic converters have crapped out at the same time, but because you're throwing both codes, there's something in common between bank 1 (cylinders 1, 3, 5 on passenger side) and bank 2 (cylinders 2, 4, 6 on driver side). Possibly a leak somewhere along the intake (i.e., anywhere between the MAF, along the intake plenums, down to the fuel injector rail and intake manifold atop the engine), which changes the air metering the engine expects to burn. There are metal gaskets at every connection; maybe there's a leak. Could also be coil pack(s) related, but again, it's likely something in common...one bad coil pack might only trigger one of the codes, but not both. Last time I was chasing those codes (P0430), it was due to ill-fitting fuel injector o-rings when I serviced them. It was a frustrating process to figure it out, eventually discovered using a smoke machine to detect the leak. Lastly, the oil leak. Does seem likely valve covers. I think the gaskets tend to leak at the front corners of them, near the 1 and 2 cylinder coil packs. They do require RTV sealant in those spots and it wouldn't surprise me if it's time to re-seal those spots, particularly if it's not been done within those 277K. If you're planning to investigate the P0420/P0430 issues on the engines top end, it's a good excuse to tackle the valve covers when you get things pulled off anyway. The Engine Mechanical (EM) chapter is your friend here with all the torque specs and bolt tightening orders. https://www.nicoclub.com/service-manual?fsm=Pathfinder%2F2002%2Fem.pdf. Page EM-38 shows the points where RTV needs to be applied on each gasket. Overall job will take a few hours. Not a fun job, but also not too difficult.

This generation of Pathfinder (96-04) I've highly regarded as being Nissan's bastard stepchild. It's "similar" to all other Nissans of the era, but almost never the exact same. The VQ engine is no exception. Some internal parts interchange, but beyond that, they only have some commonality in terms of dimensions and specifications. The same is true for the drivetrain and suspension, which is largely similar to other Nissan trucks and SUVs, but also completely dissimilar in enough ways. In the end, there's very limited aftermarket support. I also get a lot of parts from international sources like Amayama.com (Japan, UAE) and Partsouq.com (UAE). VQ35 parts might be your toughest parts to find, but across all R50s, the only real differences where the engines used. Everything else on the chassis, including transmission, drivetrain, and suspension will pretty much be identical.

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