maxdaccent
Newbie
ok am a newbie on this site but wanted to start with this as its been bugging me know for a long time. I have a 2001 Hyundai Accent which has been modified it has a 4-1 manifold with the older models CAT which has 1 o2 sensor in front and 1 o2 sensor after plus a full 2 inch stainless exhaust system, CAI and uprated throttle body, yet it just will not pass emissions on an MOT is there abody that would be able to tell me WHY? ive has a sports CAT on and it didnt pass either so bought a standard 400cell CAT but still the same problem.