Ok My friend's trying to get me to gut my main cat. I have an 88 N/A so I understand that the 5/6 th ports are opened by backpressure but shouldnt the 2 precats provide plenty to still open them?

Also, how bad do sound levels get when the main cat it gutted? I'm running a custom 2.5" catback with Apexi N1 can.

this won't be permanant, as I'll be putting on a header and presilencer at a later date..

 

I'vbe got an 89 GTU, and I just gutted the cats, it was severly clogged, the second pre cat had been pushed back into the main cat... It didn't sound bad, and It added a little HP. With my 89 the 5th and 6th port acuator is attached to the cat, and it seemed to run just fine gutted out, however I am now switching to the full RB set up header, pre-silencer and cat back. I hope it sounds good

 

Well I said F**k it and did it.

Results:
-Exhaust note is slightly deeper, slightly louder
-5/6 ports still functioning.
-Call me crazy but I swear I can chirp 2nd way easier.
-mmmmm.... gas smell....

 

have fun with emmisions now..........................

 

emmissions are for californian politics
Let her stink man.

 

gutted cats are so ghetto. if the car runs, drive it until you can afford an exhaust system. i have a header back system i paid a total of $330 for. RB uncollected header - custom pipe - RP catback. i bought it all used and saved a lot.

 

"emmissions are for californian politics
Let her stink man. " Yes I know but when you have to go register yor car again.

 

i was gonna put ina test pipe but now im deciding to just get a down pipe (its a 87 TII) and gut the main cat cause i still need to pass a visual inspection

 

I re-registered just fine here in south texas. It all depends on the local laws. But california is the main state that I know of that is STRICT on emmissions.

 

Let me tell you folks about a little place called canada..... no emmissions here

 

Ontario has emissions, as to many other areas.