reducing backfireing
 

is there a way to reduce backfireing while decelerating? anything that should be cleaned or adjusted?

sounds like you have exhaust leaks.but you didn't give any info on your car,engine,setup etc,so i'm guessing here.

its a 87 gxl 5 speed na s4 with 70k miles. its got cs headers, cs catback, hks intake, stock main cat with split air pipe connected. the port actuators and everything are still there.... when the engine is at normal temp it back fires and pops the most, but when its cold it doesnt at all.. thanks for the help

still running the air pump?

yes

then you must have some leaks on your exhaust brother.

agreed

most likely leaking between the header and main cat right?