So I have a couple of questions for you guys, here is what I'm facing: I have noticed recently that my 03 G35 started to "rev hang". What I mean by this is when let off the gas, the rpm falls slow and hangs around 1500-2000, but falls when I flick the pedal (still not normally). No problems at idle. I have checked vacuum stats with obd2, steady around 20hg at 2000 rpm, MAF readings are ok, air filter good. Throttle doesn't stick, only happens while driving. Buddy says transmission issue... But I don't think so. I haven't touched anything under the hood, except replacing an o2 sensor (b2s2). What may cause this?

Any input would be greatly appreciated.

Ps: OBD code P0455 (EVAP gross leak detected) comes and goes. Not sure if it's the gas cap. Can an EVAP leak cause rpm anomalies? Can the weather turning into the minuses play a role? Is it the tranny...?

 

When was the last time the TB was cleaned? Could be a sticking throttle body.

Also, vac leaks CAN cause a hanging idle, so you might want to investigate the source of the EVAP code.

 

I am not sure when the TB was cleaned, i just got this car, very cheap and it is used and abused. I am not suspect of the TB though, this only happens while driving, normal when in P. Now I'm starting to think that it is the tranny, i have researched the phenomena and seems to be it. Going to do a drain n fill this afternoon and see if it helps any.

 

So the drain and fill hasn't solved the issue. Unless there is permanent damage to the tranny, or the fluid that remained in it is still too dirty (the guy filling ot was amazed ), the problem sould lie somewhere else. I am going to cleann the TB in a couple of days and see what happens.

 

So it is definitely not the TB valve or a vac leak. Just tested the valve and vac with OBDII while driving.

 

I may have found the problem... After downloading The service manual, I have performed the TCM self diagnostic procedure which has indicated a malfunctioning torque converter clutch solenoid, which makes sense now that I think of it... It probably doesn't release sometimes!