carwilef7

I had some of those codes at one time, but they seem to have stopped once I fixed the flooding problem (coolant temp sensor - never got a code for it though) seafoamed it, and ran it hot -+3000rpm - occasionally by going 65mph w/ the O/D off. That burned off the goo. Good info to have though - if it comes back. THANKS!

I joined this board well after all of this was in the works, while I was fishing for answers to truck problems (to which I received warm and helpful replies - in contrast to sarcasm and sarchasm on other boards), but it's stuff like this that makes me realize there are places in the world - and on the net - where people actually give a rats a**, and it proves we're not all a bunch of self-centered troglodytes! Go MR. JIM, and thank the rest of you for being good people. I'm proud to belong here. <<wandering off to paint on a cave wall....

To each his/her own, i guess. IMHO, as a bass player and sound tech, no factory speaker or stereo was ever worth a plugged nickel after a couple of years. The electronics are cute, but not robust enough to withstand the constant motion, and the speaker materials are cheap and deteriorate rapidly. My aftermarket stuff (listed below) has done over 60K miles and still sounds great - and that's after being in a Honda Prelude (totalled by someone else), a Dodge Intrepid (POS engine locked up) and now in my Pathfinder. No matter what ya do, it's a good idea to bypass the harness wires to the speakers and use beefier ones for less voltage loss. You don't necessarily need Monster Cable, but double whatever gauge you have as stock.

I agree w/ Creekkid - dump it and get a new one, especially if it's a factory original. Same with the speakers. You can get a decent head unit for less than $100USD and an excellent one for not much more. Add at least one set of good speakers for $50 - $80, and you'll be amazed at what you've been missing. I've had a dozen or more used vehicles, and the stock radio is always the first thing to go out the window.

Thanks! I'll look into that.

Has anybody tried interrupting the MIL circuit to the ECM to install a switch? I don't want it glaring in my face all the time, but I would like to be able to read it out occasionally. I keep getting a P0420/0702 - R cat efficiency code, and I've determined that I don't need a smog test in my part of VA. I do, however, find the MIL annoying, and it doesn't look good if you go in for a safety inspection (same theory that they'll do better work if your vehicle is clean inside and out - looks like you're particular). I would still like to be able to flip it on if something goes nuts and the truck starts running bad while on the road. Lost an engine in my last car and the light was flashing for about 20 seconds before it locked up solid. I fail to see the point in spending big $$$ to replace the cat. The FSM and Haynes both show that the light is fed off a 10A bus with some other stuff in the dash cluster, and the ECM apparently just closes a contact to ground when a code is set, but I just want to make sure I'm not going to fry something inside it if I interrupt that circuit. I've also been trying to run the truck hot - O/D off and 3000 rpm for several minutes at a time - to try to burn off the gunk that remains in the cat after a bunch of fuel mix issues - all of which are resolved now. Seafoam helped - and actually made it stop throwing a code for the L rear O2 sensor., and I think that code was also a result of the fuel goofiness. I still get the 0420 code after resetting and going about 100 miles, though. Anyway - any ideas appreciated!

The thing about CFC that annoys the hell out of me is that I'm one of those "poor" folks who drives a pathy in the same year range as all those clunkers - and it makes no sense to me that they can't sell the parts off of them to help mine run up to snuff. Good that they canned the program, because if it had become permanent (never an option due to the cost) ppl like me would be forced to ride the f'n bus or drive total junk. It's not just Obama - government programs almost always have the opposite effect from the one presented to the public. It was a sop to the car companies from the beginning.

Try bypassing the factory amp (if you have one) and the harness. Kind of a PITA, unless you have some spare speakers laying around, but I'd bet the harness is messed up or unhooked somewhere - possibly inside one of the connectors. Since you say you can read impedance at the head unit connector ( I assume the speaker side) try the head unit side. Also, some newer head units refuse to work if there's even one speaker lead loose. Some will come on, but not put out sound if the antenna ground isn't right, or if some other ground is iffy. I once had an Alpine that would do that unless the power antenna wire was hooked up to the key-switched 12V line.

Sorry to rehash this, but maybe it'll help someone out: For some time I had been having hot-start flooding issues with my R50. Finally found the cause to be a bad coolant temp sensor (the one the computer uses to help determine fuel delivery, not the gauge sending unit), replaced it and no more flooding. Never got a code for it ever, just happened to run across the idea by googling, and found mine to have crazy high resistance while hot, but normal when cold or after waiting 20 minutes. Then, the MIL light came on and I kept getting codes for a bad L rear O2 sensor and sometimes for R catalyst efficiency (P0159/0708 and P0420/0702). My theory was that all the flood-start drama had gooped up the cat and the sensor, and it just needed to cook off. On Sept 1, I seafoamed the intake and put some in the fuel tank, then drove it normally for a week. Changed the oil on Labor Day (7th) and read the codes out/reset (with the screw-turn method). Have been over 100 miles since then - a mix of short city trips and 65 mph runs - and the MIL has not come on again. I think the seafoam did the trick! btw - I'm really impressed that an engine with 149k on it - with no signs of a rebuild - will make a vacuum gauge sit rock-solid at 20 in/Hg, and bounce down, then up, then settle back exactly like it's supposed to when I snap the throttle!

Precise1 - Sorry - didn't mean to blow you off. You had no way of knowing the pipes weren't in ideal shape. I guess I'm bad about asking questions and then dwelling on them and winding up on a whole other trip when someone does reply. I'm still interested in those hub center caps, btw. Tomorrow, I'll try to post a pic with the one I have and some rulers so we can see if they match before we negotiate.

$3400???????? Didn't pay much more than that for my whole truck! Try a used trans.

Will do! Thanks for the ideas!

Good idea on the torch-cleaning. It occurred to me to switch them - trouble is I don't think the wires are symmetrical in length. In other words, the right sensor wires won't reach the harness if it's in the left pipe. Also not big on pulling anything just yet for fear of breaking rusty pipes. Dunno how old they are - truck has 149K. Seafoamed it today and blew tons of crud out the exhaust. Runs like new, not that it ran bad after my initial going-over to replace filters, plugs, wires, cap, rotor, etc. When I first got it, the plugs looked like they'd been in there since Nixon was president. Anyway, I'm gonna run it a few days, reset the ECM again, then see if I still get any codes. If I do, I might try to torch-clean the one that's acting up - and attempt a switch - before replacing it.

Wait, wasn't there a hooti and the blowfishii???

having always been a cheap bastard, I've used Dawn forever - and a stiff brush. Pretty sure the plural of Elvis is "Elvi"

I used that stuff in an '82 Cutlass back in '94, about 150k on it - can't say it hurt anything, but it did seem to help with knocks and ticks. Don't expect any miracles. You can free up gunk and make stuff move better, but no additive will repair mechanical wear and tear. Sometimes it's better to just change the oil and filter every 3k and leave the crud alone - if an old gasket isn't leaking, don't fix it. In a similar vein, don't go to high mileage oil until you see leaks. When you need it, you need it - if you do it early, the benefit is gone when you actually do need it. :02:

Hope it's not the cat - don't think so. Last few days, ever since I found the @#$%$^&* reset screw on the computer, I've been reading it out and resetting it every time the MIL light comes on (same code every time). After each reset, I've kept track of which trip I was on when the light came on again. Something like this: 1st reset - 2nd trip 2nd reset - 2nd trip 3rd reset - 2nd trip 4th reset - 3rd trip 5th reset - 6th trip (!!!) All the trips were about the same for speed and mileage. If that trend continues, it could be that whatever is in there might just need time to cook off.

Exactly. Two cats, two pre sensors, two post sensors. A set for each bank.

It's a decent bet. Dunno if there's any way to successfully clean one. I'll try to pull it this evening and see.

Autozone here is useless - they can read the codes (incorrectly) but they can't clear it. They got sued for clearing them or something. I can read it out and clear it myself with the screw on the ECM. The SES/MIL light will come back on on the 2nd or third drive after that with the same code. Unless it stops acting up or is replaced, it'll probably keep coming back. I think you have to have a number of driving cycles with no probs to pass. Inspection isn't due until next April, so I guess I've got plenty of time to figure it out. Just wanted to see if anybody had any other possible causes before I spent $90 on the sensor.

Not that I'm aware of, but I've only had it since April, so who knows? The flooding to which I alluded had to do with fuel dumping on hot start-up - now apparently fixed. It would get a crazy-high value from the Coolant Temp Sensor, go into "WTF?" mode, and flood out. A new CTS fixed that problem, but this problem may have been a result of that one.

Does anybody know if a downstream O2 sensor (left side, after the converter) could seem to test okay with a voltmeter but just be lazy enough to set a P0156 code (0708 with the screw-turn method)? The FSM code explanation hints at slower response time than expected. Heater resistance, B+ voltage, and running voltage readings seem okay. I wonder if maybe all those flood-start attempts prior to coolant temp sensor replacement might have damaged it. Can't think of any other reason only the left one would do it. Any ideas? No running/idling problems, since it only really measures cat efficiency, but I doubt it will pass VA inspection that way.

I had a bad MAF when I first got mine. It would idle okay for a while and sometimes drop to 400 and stall. Other times it would just fall flat on acceleration then stall. One night it blew gigantic clouds of black smoke and just kept refusing to idle at all. Replaced MAF and a split intake boot at the throttle body - fixed it. 95+ will set a code for MAF - dunno about earlier models.

WAY easier method with less timing involved - turning the screw on the ECU. On my XE, the ECU is located to the right of the steering column. The screw is on the far upper right side of it, presumably to keep people from idly messing with it. Pull the lower dash cover from under the column - two screws, plus one in the kick panel to get to one of the dash cover ones. Remove any wiring connectors so you can get the cover out of the way. Two nuts hold the ECU onto a bracket - remove them and slide the ECU back (toward the front of the truck) and down out of its upper clip. You may have to carefully rotate the ECU to get it so you can see the screw. Mine had a clear plastic label over it, making it impossible to feel with fingers. Make sure you have located the screw with the curved arrow mark near it. Turn the key to "on" but don't start the truck. Using a flat blade screwdriver, rotate the screw fully clockwise and hold it for at least two seconds, then turn it all the way back counter-clockwise - you can now read the codes by counting the flashes from the CEL/SES/MIL light. To clear it, turn the screw fully clockwise again and hold for two seconds, then turn it back. Turn the key to "off". Now start the truck and the CEL/SES/MIL light should be off - unless there's another issue someplace that wasn't fixed before reset. Once you know where the screw is, you can probably use a flat driver bit (for a drill) and reach up there blind without removing the ECU again. To reinstall the ECU, make sure it slides into the clip at the top, re-align the studs with the bracket, and tighten the nuts. Then re-install the lower dash cover and you're done!

I say pay it forward. Drives me crazy when ppl post and post about a problem and never post the fix. Hey, does your XE have the black plastic hub center caps? I'm missing a front one with the hole in the middle and can't find it anywhere. Nissan wants 50 bucks for it!