I recently obtained another Trans Am about 2 weeks ago the car runs fine but yesterday when i started the car it sounded like a gunshot sound or firecracker and i tried starting it again and it turned on like nothing happened so today i started the car again and this time it sounded like 45 went off i am not sure what could it be it did not use to do this when i got the car i bought it off a guy that was going to junk it due to his dog tearing up his interior the car has flow master 40's can it be that it is the exhaust or is it the engine has something wrong it felt as if it came from the bottom or side of the car i haven't tried to started anymore because it sounds really loud the car is a 1989 trans am 5.7

 

a dirty or damp distributor cap could be causing missfire and the bangs-once with my '69 camaro, i washed the engine-started fine then got out into traffic and suddenly bang!-backfire through carb was strong enough to partly blow out my carb gasket