Friday morning I took the Camaro to work. About 5 or 6 times the Service Engine light came on shortly after a throttle stumble. I ran the codes, and sure enough, I got a code 33. Later in the day when it was warmer, the car ran ok (or at least as good as usual) with no codes and no stumbles.

This morning I took it to work again, and I had the same thing. I had the throttle stumble and the SES light came on 3 times.

What bugs me is that everything is brand new. Recently I was fighting a never-ending code 34, and wound up replacing the MAF, the MAF relay and the ECM.

Any ideas here?

Isn't Code 33 the MAF gm/sec code? Are you exceeding 45 grams/sec of air and that is setting it? The only way to tell is to raise the threshold in the chip...but then again, I don't know if the 870 chip is the same as my 165...

Just a thought...

33 is the voltage too high code, which I would imagine translates into an unrealistically high g/s number. I don't think raising the threshold on the chip will really help. I mean, it might stop me from throwing the code, but it's not going to stop the car from bogging.

I'm just wondering why it only does this in cold weather. I drove it again at lunch and it was fine. it's only in the morning when the temps are in the 30s that it does this.

Sluggish TPS or CTS?

No, they are both fine.

As expected, the car did it again on the way to work this morning. I'd randomly get stutters and stumbles while cruising. It's really frustrating because I can't understand the connection between the cold temps and the faulty airflow numbers.

hey jim,my recently purchased 85 iroc with 78k miles is doing this very same thing,when its cold it runs like crap,stumbles,misses,ocasionaly backfires,once it warms up after even a short distance,the ses light goes away,doesnt come back unles the car has sat overnight and fully cooled down.

im tryingt to trace the problem right now

Either of you find a solution to this?

Every night when I leave work (11pm or later) and it's cold out, I can get about a mile down the road and the car will stumble for a few seconds, then about 5 seconds later, the SES light pops on and stays on for about 15-20 secs. Will do this 3-4 times over a 20 mile trip.

Only does it when it's cold outside...