recently since I was forced to hook back up the air pump on my trans am and I replaced my MAF my exhaust has has been giving me a funny sound if I rev it up and let off quick. kind of like the sound of a backfire but not quite. I've got a zz4 engine with a stock tpi intake(that's about to go bye-bye) and a slp exh w/ 1 3/4 headers although I still have the stock cat. Other than that sound the car runs fairly well. Every once in a while if I hit the gas just right off the line she pauses a second before she takes off. Any help would be a blessing. Thanks, Josh

 

As far as the pause in acceleration, check your plug wires and make sure one isn't burnt.

 

maybe its possible that having you pump off then putt in back on started to clog you cat in some way