I Have An 03 Track And I Just Installed A Set Of Invidia Test Pipes Things Were Fine For About 100 Miles Then It Threw A Code Saying Cats Arnt Working Right .. Ive Deff Noticed Gas Miliage Went Way Down But My Question Is

1. I Thought The 03 Didnt Need Non Foolers And
2. Is It Bad To Drive It With The Sel Light On Or Will I Just Burn Gas Quicker

Thanks Guys I Searched But Cant Seem To Find What I Need

 

Your probably getting bad mileage, because your driving style has changed since you installed your test pipes. Put some non foulers on them and I'm sure the code will go away.

 

when i put test pipes on my 03 i got the same code. i deleted it though with my scanner and it never came back.