So now the 02 sensor has been replaced, and now I'm getting a rough idle in park and in drive, to the point in drive that the car feels like it'* cam'd? Any thought'* or suggestions? Also today I took it out on it first 100+ mile trip and when coasting in D the RPM'* fluctuate between about 900 to almost 2000 and when it hits about 2000 it will actually accelerate the car......Wierd.....Any thought'* on this one too? I was forced to run 90 octane today when I had to fuel up, but I did run some octane boost when I filled up. Also what is the average mileage that this car should get? What does everyone else get for mileage?


Thanks,
Nate

bump

Have a hard time believing that no one really has any good ideas about this?

was it the o2 sensor that caused this? was it an ac delco unit? maybe resetting the ecu will help.


-justin

Lopey idle in D.... That would seem to me that it indicates the PCM can't control the engine well enough, like one of it'* sensors isn't returning a correct value or those values are being offset by a mechanical condition. Now how that would happen has got me... Could be anything from a lazy sensor to a vacuum leak...

Or pull your TB off, and thouroughly clean it, especially the IAC port/seat. The fact that it does this after warmup is a real solid clue in this direction.

O2 came from Dealer.....I will clean the TB when i get home tommorow (got more CAI work to do anyways) I have a PCM scanner and have claered codes out, and problem persists? Maybe Disconnecting the battery? Thanks.

If you clear the codes, and the codes come back, you still have a problem. You can't erase a current code.

I didn't think so, but it'* not throwing any codes other than the QDM 1 which I don't think would have anything to do with this.....And it'* an occasional code

Back to your original post:

I don't see anything here that would be related to QDM1 (or QDM A). But that'* still a problem as I stated in the other thread. You should track this down.

What I would do at this point:

1. Delicately clean the filaments on your MAF sensor with rubbing alcohol and a Qtip. VERY delicately. If that doesn't help, try running with the MAF sensor disconnected.

2. If that doesn't work, buy a TB gasket, and remove your TB for a thorough cleaning (with the MAF and IAC removed). Clean the IAC and it'* seat in the TB very well.

On the octane issue, most over the counter boost products raise your octane one point. Thats POINT one. You were running 90.1 octane after you put it in.

I don't know what most get, but I get 29-30 mpg on the freeway at 70, and a recent trip to Seattle at 80+ netted me 25mpg.