When letting off the gas (in gear) the car (95 GT 5.0 with T-5) makes a noise towards the engine area that almost sounds like a jake brake. Car has shorty headers, off-road H-pipe - not sure if it’s exhaust related sound or what. Any thoughts?
Engine could be shifting on the motor-mounts when decelerating with the headers banging on something. Engine could also be popping into the exhaust (a bit of extra fuel on deceleration) which is louder with headers and a no-cat h-pipe than with stock. Not sure if I could guess better with sound available, but I'm interested in what you're describing.