I have an '02 WS6 Trans Am with 53000 miles on her. I've been getting bad gas mileage and a little bit of a back fire comin out of first sometimes and once in a while comin out of 2nd. I have just changed my plugs and wires and they were obviously not the problem. I'm thinkin my fuel to oxygen ratio is to rich. Any suggestions on how to fix my problem?

 

check your fuel filter and O2 sensors, clean the MAF and air filter as well.

 

are you sure its backfiring and not just the exhaust cackling