Catalytic converter delete

[coreydmc]

Hello everyone...I need to replace my exhaust manifold gasket on the drivers side. Is it a good idea to remove the cat since they are not required for inspection and emissions anymore in N.J.? Is there anything I would need tune or adjust or can I just remove it and use a delete pipe? My cat is not original I think it is a Harvey Special T cat. Not sure if it even works......
Thanks
Corey

[David T]

Unless you convert to headers, deleting the cat isn't going to make much of a difference except that you will notice the exhaust will be a bit louder. In New Jersey they actually look to see that the cat is physically there unless you are plated Historical.

[AirmanPika]

Having done this myself for similar reasons (and not wishing to try to source a new heat shield...the old asbestos one was trash) I can't say I really notice much of a diff in performance. It was more out of simplification. Luckily in my case I don't have my car registered where emissions are a thing so it wasn't an issue.

[vwdmc16]

About 8 years ago I did a chassis dyno test comparing stock exhaust with a gutted cat that I welded a section of tubing in. No other changes
I gained 1 ft/lb of torque, no measurable change in Hp. I can dig up the dyno chart off my old computer.


Imo it's not worth it. It just makes the exhaust smell which bothers some people.

I wrote up a thread that showed a back to back dyno test of stock w/cat vs DmcH exhaust, a much better flowing system than stock. That gave a decent 15% bump in HP .

http://dmctalk.org/showthread.php?11587-Stock-Exhaust-vs-Stage-1-Exhaust-Dyno-Tested-Results!