specs on my ride
2005
miles: less then 8k (yes 8k not 80k!)
motor mods: K&N Typhoon c/a (no ebay crap)

ok here is the deal... when driving my car under heavy driving conditions the car will go into limp mode, then im forced to do a quick learn reset to get the thing back on the road... when driving normal, its a little less likely to happen but still does OFTEN. ok the weather yesterday was like 82 degrees outside, while driving my car around with the air so hot, the car GOES INTO LIMP MODE! (and thats under very normal driving conditions) this is really getting to me... the car was doing this BEFORE i put on the cold air, thats why i picked up the K&N cause i thought it would solve the issue, it didnt, this has been happening for about 2 months now (since i have owned the car)... the CEL says that the issue is the TPS... yesterday i changed out the throttle body & TPS from a new one at Nissan... the issue is there STILL. any ideas, this is spinning me and making me sick to my stomach

 

Try cleaning the MAF sensor. Could have gotten some oil or something from your intake filters. Doesn't sound like you've done that yet. Also, check to make sure it's connected securely.

 

the MAF is on the intake correct? just checking... what shud i clean it with and how shud it be cleaned... and if the MAFlow is the one causing the issue, why would the CEL throw a TPS code? but ur right, i never cleaned it.

 

after checking the MAF sensor, check your clamps on your intake. Make sure it is properly sealed to your throttle body. It would take a serious vacuum leak to send your car into limp mod, but it's possible. It sounds to me like you have a long list of things to eliminate, so start with the obvious then work your way into replacing things. Not the other way around..

 

i will go check to see if the MAF is in securely BRB... actually, i will take a pic

 

pix uploading... 2 mins.
all clamps are sealed tight, i replaced the throttle body and did it all myself. clamps are super snug.

 

Isnt this all under you warrenty?

 

 

perfect question... the car was a personal buy + its salvage title... we were all just talking about this last night... is there any way around this... these cars COME WITH a 3 year / 35k warranty right!?

 

Correct. You can clean it with Electronics cleaner from any auto body store. It may not be the problem, if it's throwing a TPS code, but it's better to cover all of the bases.

My Sentra acted similarly, but didn't throw the TPS code. Ended up having to replace the MAF, because it was defective. Dealership said my intake oil didn't foul it or anything.

 

got it... i will go cop some now... shud i just remove it and spray it down or shud i scrub it with a tooth brush, i dont want to damage a part that my not be damaged already

 

just spray it, and let it sit. NEVER touch the element in the MAF with anything.

 

ok ok... pull it out- spray it - let it sit... check.

 

Yes they do, But if you have a salvage title it might not be covered under warrenty . I dunno????

 

this is kinda a PITA, but another problem i ran into. The hose that connects your intake to your engine, that runs underneath the intake. Check this for cracks. I had to stretch mine out to fit over the stock hose that connects to the block. During this process i cracked it further down the line and didn't know about it. after about 6 months of rough idle issues i pull the intake off to discover this. Replacement hose was $2.50 which was acceptable considering how aggravated i was at that point. Just another possibility. The fact that your car is a salave title, your warranty is more than likely void. Sorry mang, good luck with things.

 

by any chance have you replaced the accelerator pedal with assembly...its 1 piece. Sounds like the accelerator pedal is sending to much voltage to the TPS and cause the car to go into limp mode. It will throw a TPS code and most people will automatically look to the TB. But your symptom sounds almost text book 4 the accelerator pedal assebly.

 

ok... i cleaned the MAF with electrical parts cleaner... took the car out for a little heavy driving and when i hit the same turn in the canyon that it normally goes out on, it did it again. its almost a combination of a specific amount of G's and speed that causes it to go limp. didnt fail tho... hit the turn, check engine light, limp mode.

still sound like a accelerator pedal issue?

 

what hose, the one that DIRECTLY CONNECTS the intake to the throttle body? mine is perfect if thats the one ur talking about.

 

Hmmm yeah I think so, Mine did the same exact thing. And especially if thats the only code its throwing up. The accelerator pedal sensor and assembly should be covered under warranty. The part is on back order also FYI

 

You're wasting your time chasing problems that aren't there by cleaning the MAF, and checking hoses. The PCM isn't stupid, if it's throwing a code about the TPS, then the problem is related to the TPS. What is the actual code pulled? It will at least give some clue, (ie. TPS signal voltage too high...etc)

Your best bet is to use a scan tool (if you have one available) and look at the PIDs to see what TPS% and TPS V are. TPS V should be ~0.5V at idle, and ~4.8V at WOT. % should change accordingly. It works off a 5V reference so if there is high resistance in the reference wire then reference voltage will be low, which will result in signal voltage being low.

This is just one of many possibilities and for me to diagnose it over the internet is nearly impossible.

I understand that the Z is drive by wire, so there is most likely two TPS's. I believe I read the other is at the pedal. You at the very least need to know which sensor is the culprit before you continue doing anything.

One thing I can say with certainty is, don't just throw parts at it, and don't just look for anything that people advise you to check on these forums.

Throwing parts at it will cost more money than to have someone properly diagnose it, and checking for problems that don't exist will just waste time without making any progress.

I advise you to take it to a dealership and let them fix it. This is what I do and most of the time, the backyard "mechanics" who try to fix it themselves, waste money on non-fixes, and often screw something else up because they didn't know what they are doing. Nissan has the proper diagnostic equipment to find the problem and fix it the first time, assuming they have competent techs working there, which they should.

If you want help, I will gladly offer, but without being in the car with my scan tool, my help will be limited to speculation.