same o'j

I have a problem you guys might help me. I had a y pipe on my camaro and now i installed kooks true dual x pipe. And after installation at 5000 rpm and over my car backfires and is very rough. Does that mean after installation i have to tune it? And if not what could be the problem?
one more thing my spark pluge are new just now changed
thanks

forecastvideo

does it happen while your still on the gas? or after you let off?

same o'j

yes, while i still on the Gas ???!!!

Paul 75 L82

iTrader: (1)

Have you checked your codes, maybe you have an O2 sensor not working.

Jon@Texas-Speed

iTrader: (18)

Make sure the plugs aren't damaged and the wires are pushed all the way on.

Jon

same o'j

the tuner already cancel them

same o'j

every thing was checked ,and 4 days age i change the spark plug with NGK TR6 , wires are good , i inspect the car with TECH2 i found only this code
( p1637c ) !!!!
do you guys think its need to tune up ???