Hey guys.

I'm going to try to be as detailed as possible while keeping it short as to not bore you guys.

My 2003 Base 350z is approaching 100k and I'm doing (preventative) maintenance on it as it gets closer. Cleaning the MAF sensor and TB was one of the tasks on that list.

Here is how the procedure went:
1. Disconnected negative terminal from battery
2. Disconnected and removed MAF and sprayed it down with CRC MAF cleaner as instructed on the bottle
3. Disconnected and removed the TB and cleaned it with TB cleaner. Yes, I did move the butterfly to get every bit of grime
4. Put the TB back and tightened the screws in the order required as per the FSM
5. Put MAF back and reconnected battery

I then did the "pedal dance", making sure I took the car for a spin to get it to operating temps before performing the final relearning procedure. During this drive, I noticed the idle was a bit high (1100) and there was "rev hang" whenever I let off the throttle. I thought nothing of this as I figured it would go back to normal after the final procedure. Once I completed the final relearn, my idle was a little bit over the 750 mark. I take the car for a drive but noticed that the rev hang was still there and the high idle returned shortly after.
So, I repeat the pedal dance, always making sure the car's conditions met the requirements of the FSM for the final procedure. Somewhere during all of this, my SES light turns on. I didn't freak out because I was certain it was warning me about the high idle.

I take it to Pep Boys the next day after work to get it pulled and was surprised at how many codes were pulled. These were what the scanner brought up:
P0507 Nissan - Idle Control System RPM Higher Than Expected
P0123 Nissan - Throttle Position Sensor/Switch '1' Circuit High Input
P0223 Nissan - Throttle Position Sensor/Switch 2 Circuit High Input
P2127 Nissan - Accelerator Pedal Position (APP) Sensor Circuit
P2122 Nissan - Accelerator Pedal Position Sensor Circuit Range/Performance

Mind you, I was well aware of the handful of people that had problems after cleaning their TB and the minority that had no issues whatsoever. Due to how meticulous I can be, I usually end up among the ones with a happy ending.

I've read that I could have possibly messed up my TB by moving the butterfly. I've also read that the ECU could be the culprit due to the lack of a fuse between the TB and the ECU so I could've possibly shorted out the ECU (something along those lines, don't quote me on that. I can't find that thread now).
But these codes are leading me to believe that my pedal has a role in my high idle and rev hang. It just seems too coincidental for it to go bad after cleaning my throttle body.

I have since reset the SES light and performed the pedal dance numerous times to no avail.
I've also tried disconnecting the battery overnight. The SES light was gone in the morning and idle dropped to about 850 at operating temperature. Rev hang was still there and high idle returned after driving about 2 miles. SES light would turn on on the next start up.

I'm looking for any feedback that can lead me in the right direction. I tried to be as thorough as possible. If there are any missing information that you think might help in resolving this, I'm more than happy to answer.

I am trying to avoid a dealer or a shop, however, if I must....

Thank you in advance!

 

I had p0507 in my G and I removed my tb cleaned it. I moved the butterfly and used steel wool on the edges. Reinstalled using a new gasket, did the relearn and all was good. It's strange that this happened afterwards. One step mentioned was to check for intake leaks. Do this by spraying tb cleaner on the connections and listen for a change in idle speed. If u didn't use a new gasket I'd suggest trying that. Nissan part # 16175-ar000

 

I did replace the throttle body gasket with a new one. I didn't know if it was direction specific when I put it back on so I was afraid there might've been a leak. That's when I sprayed the TB cleaner around the gasket area of the TB to check for any vacuum leaks and there was no change in the engine speed.

 

Take it to dealer for idle relearn.

 

I had the exact issue as you. Page three has solution.

https://my350z.com/forum/maintenance...-any-gear.html

 

Thank you for your respons!
I read through that whole thread. I'm glad you got your high idle fixed! Did you happen to pull the codes while the SES light was on? I'm wondering if you only had the P0507 code for high idle or additional codes similar to what mine is throwing.
I need to call a shop that specializes on Z's tomorrow and see if they have the computer that Nissan uses.

I did the first two relearn today after I got off work and drove my car home. By this time, it was at normal operating temperature. I let it run while I jump the battery to my brother's car that was running as well. I did this to make sure that the battery voltage was well over 12.9 while I'm doing the final relearn.
Same thing happened =/ Idle drops to where it should be but returns after a few runs around the block.

Gonna' try and get some DMM readings tomorrow at the sensor plugs.

Please chime in if you guys have any experience with the codes being thrown. Thank you!

 

When you cleaned your maf did you spray the maf or use the q tip method to clean it? Perhaps you used to o much cleaner?

 

Hey, thanks for the reply.

I did not physically touch it with anything. I sprayed it with MAF cleaner from afar. I'd estimate it to be about 4 feet, give or take, with the straw on.

 

I cleaned the TB. Without removing it. I got the SES light and idle was above 1k. I tried the relearn a number of times with no luck. I even disconnected battery for 24hrs and still didn't fix the high idle and SES light on. The codes it throws are what you described. Took it to mechanic. He had the nissan tool the dealer uses. I watched him do it. he just pressed the idle relearn and something else and boom problem solved. Idle back to normal the light went off and all is good. I've put 100+ miles on it since and it's still running good and no SES. The relearn just is not a sure thing so much easier to get it done right

 

I emailed one of the Z shops around my area to see if they have that tool. There's another shop that might carry it as well. Going to find out for sure tomorrow.
I don't want to take it a dealer with all the stories I've read.

Thanks for your input. Hopefully one of these shops have it!

 

Dealer quoted me $65. Not bad but not exactly cheap for a 10min job of pressing buttons

 

They charged me $50 to do the relearn. But it didn't stick. So, they said I needed a new throttle body. They picked it up the same day and had it in within 2 hours. I figured I would see my car pull out in a matter of minutes after the relearn. Turns out the relearn is still not sticking.
They checked for cracked hoses and leaks, even swapped out the throttle body for another one to rule out a defective unit. Consult II said relearn was completed but idle is still high.
It was under the knife for a couple of hours before the tech said I'm going to have to replace the ECU. He said a used ECU would run me about $300. I did a bit of googling and see a few ECUs that can be had for cheaper than what he quoted me. I have a 2003 Base model 350z. Will a 2004/2005 base model ECU work flawlessly? How about a 2004/2005 non-base, 6MT ECU? I'm trying to see what my options are because narrowing the search down to an '03 Base ECU is a bit of a challenge. Also, I've read that the ECU must "pair" with the BCM. Can someone please clarify this for me?

 

Bump. Instead of starting another thread to add to the thousands already out there, I figured I would join this one. Like the OP, I have the 507 code..... I've done the relearn and it doesn't stick just as the OP described. I'm thinking about picking up a new throttle body to try, but would hate to spend the money and have it not help. Same with going to the dealership to have it reset. This damn code is keeping me from getting the emissions test done to be able to drive it and it's not making me very happy. Any help would be much appreciated.

 

I guess I won't be cleaning my throttle body anytime soon. I guess "preventive" turned into a learning moment for "If it ain't broke; don't fix it." LoL
This really is one of the things I want to do but not now. Anyone with any sure fire tips to not cause an idle relearn visit to the dealer?

 

Since I did touch the butterfly valve.... would replacing the throttle body be a pretty sure shot at getting rid of the code since just doing the relearn isn't sticking.

 

I wouldn't say sure shot. I thought I screwed my TB when it happened and even the shop thought it was the TB. They replaced it and my problem was still there.
Try to get a hold of someone that's willing to swap to check if that is the source of your problem before buying.

 

I did the tb clean on my G cause it was throwing a code and my z just because. I cleaned the butterfly with steel wool on both of them with no problems. FYI

 

I must be lucky, I sprayed CRC TB cleaner into butterfly without touching it, battery connected. Most of the gum came off. Made d@mn sure to get both ends snug, plus the breather hose on the bottom.
My 06 was running good @ 69k, and I try to only mess with one thing at a time.
High idle on restart, smoothed out, no probs at all.

 

Just to update the thread on my situation. I just got the car back from the dealer, they programmed the new (used) ECU and all is good. Idle is back to normal and no more rev-hang. Feels like I'm driving a different car again.
Anyhow, that was one COSTLY preventive maintenance for me....