2000 Chevrolet Impala • 6 cylinder 2WD Automatic • 55,273 miles

2000 Chevrolet Impala mileage: 55,273. There is a rotten egg/sulfur gas smell every time I start up my 2000 Impala. You can actually see a haze in the air after the car is started and it takes about 20 minutes to get the smell out of the garage with the door open. It is a very potent odor. If the re-circulation vent is on outside air, you can actually smell this gas odor inside the car for about 10 minutes after running it. Can you tell me what the problem might be and what to look for? I have had new plugs installed in November, and the gas mileage is still excellent. Could it be the catalytic converter, exhaust or what? Any help and information on this matter would be greatly appreciated. Thank you.
January 5, 2011.

A faulty fuel pressure regulator may be your problem. This regulator leaks fuel into the engine when it is off which causes an over rich condition when the engine is started. This is the cause of the rotten egg smell.

Jan 7, 2011.
I'd agree with the experts opinion above. I have heard of many people having to replace their catalytic converter but not until well over 100,000 miles.

May 29, 2011.