04' G35 AT, P507---online mechanics, need advice

[510SX]

I've changed the spark plugs, cleaned the TB(I know... but it's too late now). P507 code keeps popping up. I've gone thru the ECU reset, throttle valve closed position and idle air volumn learning procedures...., the car drives better, but only last several miles and the code came back.

The symptom is when I let go the gas while I am crusing, the RPM drops 300-400 and immediately raised up. Also, when I am braking, the car always want to give me an extra push. I bought a brand new TB from the dealer few days ago, but didn't solve the problem.

Questions I have is, besides ECU reset, throttle valve closed position and idle air volume learning. what other procedures I have to do? Is there any calibrations I am not aware of?

[audtatious]

Did you check the PCV valve and for intake leaks? If so, it says the next thing is to replace the ECM...

http://www.nicoclub.com/FSM/G35/Coupe/2004/ec.pdf

page EC388

[510SX]

It's hard to believe the PCV will go bad after changing the spark plugs. I did hear some "Zeeeee" noise around the PCV hose. I sprayed around the area with carb cleaner, I couldn't find where it leaked air. I thought the sound came from belt. I will take a closer this time.

[Q451990]

cleaned the TB(I know... but it's too late now).

Could you expand on this? My instinct would be to clean the TB while I had it off on my wife's G too.

Heath

[510SX]

If your engine light came on after you cleaned the TB, mostly likely you get Code P507 which is idle air higher than expected. Do a search on this site, you will find several somebody say you are not suppose to clean the TB. some people have good lucky just reset the ECU and re-training the TB. Some people ended up buying a new TB. In my case, new TB and re training the TB didn't work.

[Q451990]

Interesting. Her G just hit 49K today, so I haven't done anything except fluid maintenence and air filters - but the day will come. I'll certainly keep that in mind.

Heath