Need to stay emission legal in GA. so I've been looking at PaceSetter, MAC and Kook mid tubes. They adds all say bolt their new Y-Pipe to the existing CAT. Problem is my CAT is welded to the Y-Pipe almost at the Y merge. If I cut the pipe forward of the CAT there is not much stock left to weld on to the new Y-Pipe that comes with the headers. Has anyone been through this, do I need to get a new CAT with the headers ?

 

The only problem is usually the aftermarket y-pipes are 3" in diameter whereas the stock cat is smaller.

 

I have a set of pacesetter mid-tube headers on my 94 Z-28, they have a jet-hot coating which makes them look great and lowers underhood temps. I got them off of E-bay there are many people selling them there. You have to cut your Y-pipe off as far from the converter as possible, I know it doesn't look like much after you cut it, the good thing is the new Y-pipe with the header kit goes inside the cat inlet pipe (where you cut the stock cat off at). You will have to oval the header Y-pipe a a little due to the shape of the converter pipe after cutting the stock Y-pipe off but it is easier than trying to get the converter pipe round. Then you want to mock everything up (no gaskets but tighten everything down snug) make sure your cat is supported by the hanger at the rear of it, when you get it how you want it (nothing hitting anything, cat level with car, pipes straight, etc) just tack it in a couple of spots. Then you can remove the Y-pipe and cat and weld it up nice on the floor, or a bench. You will notice that the Y-pipe has a break in it where it runs under the engine, they include a muffler clamp for this but it just plain sucks, again I tacked mine in the car then removed it and welded it nice off the car. You don't have to weld this pipe but I guarantee if you don't it will leak and the clamp looks hideous when you look under the car. There are other header kits available but I liked the pace setter kit the best and haven't had any problems or leaks in 10,000 miles. Also you can get kits that are compatible with your emmission systems (EGR, AIR, etc). I hope this helps.

Dan