Warpspped y-pipe is it illegal?

 

As I'm looking into it as well, I'll try to help you out. On the 2k-2k1's the Y-pipe removes pre-cats and will make you fail an emmissions test. On the 2k2 & 2k3 it does not remove any pre-cats so it will not change the emmissions. That's what I've found out from searching the .Org and speaking with Warpspeed.

 

People have passed with an aftermarket Y-pipe and their stock cat. Greekmaxima, I suggest you search for the answer to this question.

 

You will fail emissions if you have not warmed up your car or driven around for atleast 30min with the aftermarket y-pipe. If exhaust gases are still cold you'll be runnin rich and at this point you will definitely fail.