fixinto

i believe running too many fuel additives or running pretty rich my cause that. "dont quote me on it" think i read it somewhere tho.

i would address the exhaust leak, if its under hood its probably pre cat. After that if nothing improved i would throw a couple of sensor 1 O2's at it, they r pretty cheap and it cant hurt. However if you want to test them, i believe you can back probe them after they are warm and watch for voltage changes when you rev the engine say between idle and 3500rpm. Just an idea. even with it being winter I'm rockin the 16mpg average. but i know there are a couple of things i can do to possibly improve on that. just waiting on warmer happy times. PS i have heard of people putting their O2 sensor in a vise and using a propane torch to heat them up while measuring the voltage to ground. if you pull the heat away they r supposed to react almost instantly. If your o2's are getting slow it will cause crappy crap crap to happen too.

^^ same thing bout the sea foam found it after my valve cover gasket replacement and tb clean. "think i posted that somewhere" dont really remember

oh ya i forgot to mention the MAF, on the side of ur air box. if it gets dirty or goes bad it can do something similar. If ur truck is running really really bad with the codes unplug it and see if it runs better. u can just unplug the battery neg terminal unplug the maf and take out the 2 screws, clean the wires with maf cleaner or alcohol and a q tip, make sure u didnt leave behind any fuzz. then throw her back in there, hook everything back up and c what u get. sorry for excluding this info on my earlier post, it completely escaped my attention. Hope you get er runnin right again. GL to ya.

the O2 sensor code is for lean. The purge flow monitor means there is a problem with the flow of your evap system? have you done anything to the truck recently? u have a small hose that plugs into the bottom of the TB housing hard to see with the tubing for the intake on. but check and see if that is unplugged. The hose runs to a solenoid "little black box" with other hoses coming off of it. Its only about a 7 to 9" small rubber hose. Either A this hose is off and is causing multiple codes. Or B the "black box is malfunctioning and making fubar? 0130 is 02 stuck in a constant condition other than 2.2v "something like that". Make sure the black box electrical is plugged up and make sure the 02 sensor is plugged up, and the wires are not broken or pulled out of the o2 sensor or connector. "easy to trace the o2 wire from the exhaust manifold before the cat to the top of passenger valve cover" also if your budget is tight and you wanna be sure its the o2 sensor swap it out with the driver side "pre cat" o2 sensor. if you CEL comes on but for bank 2 sensor 1 then u know the sensor is toast. if not well something else is causing it. and if it is still the bank 1 sensor 1 code its probably an exhaust leak pre sensor on your exhaust manifold. but you should be able to hear it if its bad enough to throw a lean o2 code. if your truck starts getting crap for mpg, try unplugging the o2 sensor and seeing if it runs better. if its a false code (such as a miss read from an exhaust leak) the ECU should revert back to previously mapped "over long peroid of time" data. that will band-aid it till u can get an o2. but having both codes at once .....the evap is not used to control the engine directly. so u may have had the code stored then the o2 went wonky on you and threw the CEL LIGHT and u just pulled them both. not sure if evap would throw a code by itself or not since its not used directly in controlling the operation of the motor. hope my hopeless rambling has helped u out even a little. i was just trying to remember everything i read previously about the o2 sensor in conjunction with the evap. " i was stuck lean" and my fuel pressure regulator hose was unplugged behind the upper intake. Anyways thats how it is on a 96 hope u get er lined out bud. arranged this a little different, wouldnt let me edit my first post, i think this is a little bit more organized and not all over the place, im kindof a scatter brain when im thinking things out and it comes out like crap in the post.....

the O2 sensor code is for lean. The purge flow monitor means there is a problem with the flow of your evap system? have you done anything to the truck recently? u have a small hose that plugs into the bottom of the TB housing hard to see with the tubing for the intake on. but check and see if that is unplugged. The hose runs to a solenoid "little black box" with other hoses coming off of it. Its only about a 7 to 9" small rubber hose. Either A this hose is off and is causing multiple codes. Or B the "black box is malfunctioning and making fubar? 0130 is 02 stuck in a constant condition other than 2.2v "something like that". Only thing i could recommend is what i already did. Make sure the black box electrical is plugged up and make sure the 02 sensor is plugged up "easy to trace the o2 wire from the header before the cat to the top of passenger valve cover" also if your budget is tight and you wanna be sure its the o2 sensor swap it out with the driver side "pre cat" o2 sensor. if you CEL comes on but for bank 2 sensor 1 then u know the sensor is toast. if not well something else is causing it. if your truck starts getting crap for mpg, try unplugging the o2 sensor and seeing if it runs better. if its a false code the ECU should revert back to previously mapped "over long peroid of time" data. that will band-aid it till u can get an o2. but having both codes at once ..... hope my hopeless rambling has helped u out even a little. i was just trying to remember everything i read previously about the o2 sensor in conjunction with the evap. " i was stuck lean" and my fuel pressure regulator exit hose was unplugged behind the upper intake. I have never had the evap problem tho. the evap is not used to control the engine directly. so u may have had the code stored then the o2 went wonky on you and threw the CEL LIGHT and u just pulled them both. not sure if evap would throw a code by itself or not since its not used directly in controlling the operation of the motor. Anyways thats how it is on a 96 hope u get er lined out bud.

maybe you have a rusted left shock tower per the FSB and its a little wonky making everything out of whack? =) i think u can get it checked at nissan anytime being a recall and all. Love the way ur truck looks, i want those tires for mine after i finally get a lift = \ Dear Santa....... Anywho have a nice day, hope you get your pathy probs worked out because the truck just looks too darn cool to not leave it that way.

ya if the knock sensor is bad and sending a bad singnal to the ecu the ecu will retard the timing when it doesnt need to. = crappy running PoS. a quick check of the Knock on the 96 is to find the wiring harness where it plugs in on the top of ur motor and throw around a 550k ohm resistor in there, if it runs better ur knock sensor is toast. =)

my pathy likes the NGK plats. =) actually my pathy like any NGK : )

well the hoses were original equipment. "had to be" they were corrode welded to the pipe that runs under the intake, and being up against the fire wall like that, "hose pliers, cussing, tugging, pulling, jumping up and down, rolling on the ground kicking and screaming, and crying in the fetal position did not get it off, so i just cut the darn thing. it was midnight on a saturday and i had been working on it since 2 that afternoon.

Howdy guys, i see that a lot of you fellows r talkin bout the 31" tires. Im not sure what his had on it factory, but my 96 SE manual has 31's factory, and i was rockin the 19mpg for 4yrs since i owned the truck. unless he had the 30" package and a different gear set than mine, i would say it should probably have 31"s on it. Just a heads up on that. And 1" of tire shouldnt make that much difference in gear ratio. when u get to the 1:1 its like, 400rpm lower with the the 31" instead of the 30" so really not much at all. I do agree if you go BIG then ya. u need to regear, but 1" isnt really anything to worry bout. Just my 1/2 cent on the matter. have a good one guys. PS im almost sure u wills see a big diff when u fix ur manifold.

http://www.partsgeek.com/gbproducts/DC/6750-05054936.html?utm_source=google&utm_medium=ff&utm_content=DN&utm_campaign=PartsGeek+Google+Base&utm_term=1996-2000+Nissan+Pathfinder+Exhaust+Manifold+Dorman+674-431+Left+96-00+Nissan+Exhaust+Manifold+1998+1997&fp=pp&gbm=a&gclid=CKuhn_eE7LQCFYLd4AodPkYA5g Found the link to the manifolds, supposed to be redone by these guys to fix the failure points of the originals. I will order them and get em on in a few months when it warms up. not standing out there in this weather and fighting with rusty/broken bolts or studs. =)

Ya i would address the exhaust leak asap. I think i saw manifolds somewhere for 45ish per, i was thinking at the time, wow thats really not that bad. come to think of it i need to do mine. that will probably get me back up in the 19 range. after i did all the work on it i noticed when i started it up and the sea foam was filtering out of the engine that i had a BUNCH of smoke comming from the passanger side under the hood. so ya, seafoam helped me find me exhaust leak. i almost forgot about it till you said something. im gong to go see if i can order those real fast. i know the pita to doing that job will be getting those studs out without breaking them (if they r not broken already) have a good one, and i hope u get er figured out soon.

be sure your sensor one O2's r hooked up proper also. a fudged up O2 will cause lean and similar problems as you described. A lot of times it is a dirty maf too tho. /shrug

i was going to make the new one long, just not curved from the side, more of a middle shot that comes out past the dizzy. and yar i know all the stuff bout the pita hoses and electrical behind the manifold, it was nuts the first time but i think it had never been off so everything was corroded on. i ended up just cutting a lot of the hoses and replacing them. "wayyyyy easier and highly recommend it to anyone pulling the plenum." and ya man if i find out anything bout my ride i will let ya know. i read a thread somewhere bout throwing a resistor in where the knock sensor plugs up and that will fix if ur knock sensor is bad and throwing everything out of whack. Since i done a lot of tweakin to mine and teakin and tweakin. it runs pretty goood. actually really good. just idles a shade too high, and likes to hang out around 1100 till i get stopped. im sure i will figure out whats goin on with it this summer "spring" ill be sure to post and let you and everyone else know. At the same time throw me the word on what ur dealer finds out cause it could help me as well our probs being similar "not identical" but close. when i first got my rig back together it was idleing crazy high like u said urs was, but that was only because the stupid fast idle cam was not working. so i just tied it back with a wire hanger and called it a day those things r like 150 bones. Anyways take it easy. PS luv eric the car guy. In the video where he pulls the pathy upper plenum, he removes the 2 "fatter" hoses on the driver side. Just for the record, ya u can leave em on and and for anyone pulling the plenum for whatever reason i recommend highly that u do.

Also if you leave your gears stock and add a larger tire it makes your gears go the other way. say ur doing 65mph on 30inch tires with a 3.73 gear ratio, u would be turning about 2715 rpm. now with the same speed and gears you put a 31 inch tire on there now ur turning at 2628 rpm according to the calculation. so either my entire life i have had my gear ratio to tire size formula fubar'ed or someone else has their numbers a little wonky. that being said. Thank you for the post, nice ideas and thought process you have there. Good job on the Koni Shock mod too. I am thinking about lifing my pathy a modest inch and 1/2 in the front and 1 inch in the rear just to offset the bumpers im building for it. maybe i will go 2 and 1/2 in the front and 2inches in the rear and that would give me about an inch of lift after bumper weight. Still tryin to figure out if i just want to go with spacers or springs or both. most deff dont want to do a SFD too much work and i spend most of my time on the road and not the offroad.

Honestly i am getting 16mpg on my STOCK 31x 10.50 tires. i was getting 19mpg before i effed with stuff while doing a valve cover job. when the wether warms up i will get out there and fix her mpg, but for now she is running strong and doing well on gas. not awesome on gas like she was but good.

ya i only took the upper plenum off doing the valve cover gasket and got a new gasket for that, i may change the sensor just for something to do one weekend tho. I'm still leaning toward one of the front o2 sensors flaking out, or the throttle body being etched where the carbon was. When the warmer weather rolls around im going to see about looking into it. Looks like i'm still getting 16ish right now. Maybe a little more. Yours getting 12 is kindof freaking me out. hope mine never drops down like that, i will have to get a new daily driver in that case. the upper plenum being such a pain is making me want to get 2 from a junk yard and cut them and combine them to make one that dont block the valve cover on the driver side. May never do it, but just a thought. Thinking about deleting the EGR stuff and cats too since they dont do testing around here.

ya man i dont know how i was getting 19 on 87 octane, i just was. and every single time i have read the codes or had them read the knock was on there, but i was getting the 19mpg and it was running correctly even with the knock code on there. so im thinkin it probably has more to do with something i did while i was doing the Valve cover gaskets. but i have yet to find it. If you have ur Knock Sensor replaced and it clears up your issue then i will go in here in a couple of months when days are longer and its a bit warmer and change it out. Oh ya, i usually drive about 19miles to work one way, and i do 55mph the whole time and accelerate slowly from stops or w/e. im sure if i did 65 i would probably get around 15 or 16 because its a difference in about 800 rps.

did you ever find out for sure what was causing ur 96 to do this? I am having the same problem right now. but it didnt start till i cleaned the TB while doing the V cover gaskets. cleaned maf, "didnt really do anything" adjust TPS, "by adjusting the throttle closed/open sensor per bulletin." its spot on. before i did the work to it, it would stat up, go upto 1200 to 1500 then 7 to 10 seconds later come down to 750. and work fine. i started getting "knocking, Pinging" on the interstate under load so i did a crap ton of stuff to it that i should have done a long time ago. "wires, plugs, button, valve cover gaskets, air filter, , distributor cap. and cleaned the Throttle body. After it started acting funky i found the the hose popped off the fuel pressure regulator behind the intake manifold, so i put that back on but its still meh at best. the idle screw in the intake is all the way in to the point that i cant turn it anymore, "i think i stripped it but dont tell anyone" . i was getting 19ish mpg, now im getting 15ish. its killing me in the face. when i clutch it the RPM's go upto 1200 to 1500 and then slowly come down as i come to a stop. the lowest rpm at idle is 800 with the heater wide open and the head lights on, no load its closer to 900. it wouldnt even be that big of a deal if it weren't for the 4mpg diff in gas milage. as far as the knock sensor, from what i read around the forum, most of our pathies has that code like all the time and it wont trip the CEL, or MiL wutever u call it. so i fugured i screwed the pooch by cleaning my old TB. and probably need to replace it. Anywho, if u figure out the problem for sure and get it fixed, PLEASE pass it on, cause i would like to know for sure that im throwin the right part at it before i do it, because most of the ones im suspecting are 150ish bux per. anyways have a good one. PS the knocking / pinging is completely gone. hehe 1996 SE 4x4 VG33e,manual 5speed trans, 31x10.5 bone stock pathy

If your exhaust manifold O2 is malfunctioning, it can effect gas milage "A LOT". depending on what its sayin. Other than that, maybe the air intake temp sensor..

Right across the river in Jeffersonville. Work in Louisville tho

ya my 96 5 speed is right at 3k at 68ish

dont do ete! well dont clean the TB anywho. if its old and hasnt been cleaned in ....say....forever! there will be a ring of carbon around the butterfly that u will wash off. only problem with that is it etches the metal and causes the air to flow different than before which leads to ... just my 2 cents on cleaning the TB unless its been cleaned fairly regularly through the life of the vehicle. ALSO the 2 hoses on the side of ur upper intake dont need to come off. that would be the coolant hose right under your air bleeder screw on the driver side top of your intake and the one right beside that for the PCV valve. they just connect to tubes that run under the intake and they didnt have them at the local auto parts places, was a special order item. however there are some behind the intake that u may as well cut during the removal and replace. hmmm what else. bah thats bout it. i replaced my valve cover gaskets a couple of months ago and did a standard tune up on it. the only thing i regret is cleaning that dang TB. ohhh ya. great time to do the #6 plug while the upper intake is off Hope this helps u out in ur quest. stay chill.

Times are hard, i could only afford new floor mats for my pathy =( she likes em tho.