Most likely a bad sensor e.G. Coolant temp, O2 etc.
It is also possible the CAT is clogged. Best thing to do is to have the ECM scanned to make sure all the sensors are in proper range.
You should be seeing black smoke out the exhaust indicating a rich mixture.
You should also have a check engine light?
One other thing is that running the AC on a car can reduce fuel mileage significantly, because it takes more power to run the compressor.
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Wednesday, June 25th, 2008 AT 3:16 PM