CEL today

[foofopps]

Ok so im driving to the store today, going 40MPH-ish in 4th, i try to speed up and the car hesitates. So i down shift and accelerate no problem. Then I come to a red light and my car is idling at 400-500 rpm, and my temp gauge is flicking just a little bit, my MPG gauge is bouncing up to 40 and back to 0. All the dash lights except the CEL are glowing dimly, but no check panel or OBC stuff lights up. When I accelerate from idling it sputters up to 1000-1200 rpm but had no problems above this in the rev range. Right before I get to the store the CEL comes on, I pop the good nothing looks strange, still idling at 400 rpm, I check all the spark plug wires and AFM stuff is snug. I go in the store a sad man. I come back out 20 min later. She starts up just fine, idling is back to normal, CEL is still on, but turns off as I leave the parking lot. On the way home the car had no problems and was completely back to normal. Long story but I tried to give as much detail. Does anyone know what happened? Is it going to happen again (has never before)? My guess is something with the O2 sensor? What sensors can make CEL come up? Oh yeah it is about 4 degrees here in chicago, but I started the car and warmed it up before this little journey took place.

[jlevie]

The first thing I'd suspect for that set of symptoms would be intake leaks. Leaks that might only cause a slight rough idle in warm weather become a much bigger problem in cold weather, which can explain why you are only now seeing noticeable symptoms.

My advice is that you find a shop that can run a smoke test on the intake that will quickly reveal any leaks anywhere. You should also have the DME scanned for fault codes, but the odds are that all you'll find is a code for a Lambda fault, which would be consistent with intake leaks.

[foofopps]

Thanks, it has been cold for a while, and on my return trip from the store I had no rough idle or anything similar to what happened on the way to the store, its weird

[genocide98]

flickering gauges makes me think battery or alternator.

when I had problems with my electrical system it would idle very poorly, hesitate, gauges would flicker etc.