stock exhaust system
1. header / extractor
2. catback (midpipe+muffler; FREE custom muffler)
3. Cat delete (test pipe), midpipe has been cut
4. Item is in good condition
scenario: after a minor upboost, on max throttle, max boost at 4500 rpm misfiring happens ...can hear crackle noises at the downpipe.... but it only happens at the rpm point not before...