Throttle position sensor/Pedal position sensor issues

[Sechsterlo]

Ok, so Im having an intermittent problem with my 02 SER. Its thrown codes 1122 and 2135, which I believe are for the Pedal Position Sensor and the Throttle Position Sensor (correct me if Im wrong). Today as I was driving it threw the codes and then I couldnt get the car to accelerate beyond maybe 5mph until I cleared the codes in a parking lot. Afterwards it runs ok, but when I come to a stop the tach runs up to 2000rpm before sitting at an idle of 1500rpm. Ive been to a Nissan shop about it about a month ago, but they only checked the sensors and cleared the codes and declared it fine. Im not keen to spend more money until I have a better idea of what the issue could be. Sensors going bad perhaps?

[nametakennow]

There was an issue with the TPS's in some SE-Rs. Check for a TSB on them. Unfortunately, since you're out of warranty I think you'll have to shell out for one.

[Sechsterlo]

If I have to pay out some money, thats fine. As long as Im paying to have the right thing fixed, rather than the techs thinking its one thing, then another, and I end up paying for a lot more than I must. Ill look into the TPS and see about a tech service bulletin. That at least would be something I can show the techs and say that its certainly a problem. I figure the sensor is going bad and was going to ask for it to be replaced anyway. Appreciate the help.

[nametakennow]

If you don't find a TSB or anything on it, post up again. I'll see if I can dig up the info on the issues I remember hearing about to see if it matches up with what you've described.

[Sechsterlo]

Ok, well I didnt find any service bulletins that I can use. Only ones I found were for the older models with SR20's.

While searching for bulletins, I did come across some info that may (or may not) help the idle jumping issue. I dont have the literature right in front of me at the moment, but I read that the throttle body can devolop some buildup, and that it can cause the car to rely on an idle control valve entirely to maintain the proper idle. So, with enough buildup, when the throttle plate closes, maybe it doesnt allow for enough air to pass, and the valve tries to compensate? If that were to work, itd be a simple enough fix for one of my issues.

[nametakennow]

That sounds utterly ludicrous, but it can't hurt to clean your TB anyway, so it's worth a shot.

[Sechsterlo]

Cleaned the throttle body, but no change. Coming home for lunch from work, the Engine light came on again and the car stopped trying to move forward. This time it also stalled out as it came to a stop.

[nametakennow]

Get the code pulled and post it up.

[Sechsterlo]

P2135, Throttle Position Sensor.

[nametakennow]

Sounds like the TPS is bad, then. I did some hunting and there's nothing official on it, but it's a very common problem. The TPS is integrated into the TB on your engine. Typically the TB is $100 or so.

[Sechsterlo]

Ok, thats not so bad. I talked to a Nissan tech, he was skeptical about that idea (imagine that, he thinks the ECU is flaking because of the Nismo CAI )...I have to think if that were the case, it wouldnt be throwing a code for the TPS. As always, I appreciate your input.

[nametakennow]

ECU flaking because of a CAI? Eh...

The ECU flaking is possible, but it wouldn't be the CAI's fault. There was an ECU reflash recall for some B15 SE-Rs as well as an ECU foam recall for some Sentras in general, but I don't know for what years exactly.

If the ECU were flaking you'd probably get more random codes, or just more of them. It seems awfully specific. Your symptoms also completely align with the sort of stuff I read about other people with TPS problems. Did/does it ever hesitate, especially right before the stalling?

[Sechsterlo]

ECU flaking because of a CAI? Eh...

The ECU flaking is possible, but it wouldn't be the CAI's fault. There was an ECU reflash recall for some B15 SE-Rs as well as an ECU foam recall for some Sentras in general, but I don't know for what years exactly.

If the ECU were flaking you'd probably get more random codes, or just more of them. It seems awfully specific. Your symptoms also completely align with the sort of stuff I read about other people with TPS problems. Did/does it ever hesitate, especially right before the stalling?

The ECU had its recall taken care of before I got the car, so thats taken care of.

It only stalled once, and that was during the last thrown code. I dont recall feeling the car really hesitate, I was keeping an eye on the tach since it was surging after I took it out of gear, and it rose, and then the rpm's just dipped down to zero and it died. Thats the only time thats ever happened.

Since then I have had the throttle body replaced, got that done today. The shop also did an idle relearn. Afterwards, no stalling, and it didnt throw any codes or a light (although Ill have to keep and eye on that since the issue was intermittent and random).

The only problem now is that its still surging when I take it out of gear. Running up as high as about 15-1600rpm then down to 750. Im going to look around and see if I can find any info on that.

[Sechsterlo]

Got some good news. Surging is gone, I got a can of MAF cleaner (definitely some deposits going on there), and did an idle relearn, and all is right with the world again.

[nametakennow]

Dirty MAF, of course. Funny how the simplest solution is often the best one.

[Sechsterlo]

Dirty MAF, of course. Funny how the simplest solution is often the best one.

I know, right? My previous car didnt even have an MAF, so it wasnt the first thing to come to mind.