MY 383 is nearing its time to be installed in the car. We are adding long tube headers and y-pipe but I was thinking about the stock cats that are still in place. It would be cheaper if I got O2 sims and welded straight pipes in their place. However if this will only gain me very minimal HP over leaving the stock cats in place I would rather keep the CATS because I dont want to pollute the air and I think it would be a little to loud with a moddified 383 , long tubes and flowmaster muffler without any CATS.

Or is leaving the stock CATS on just asking for trouble? Will I clog them up with the heavy breathing 383?

I am thinking to get a Flowmaster CAT-Back system to go with the long tubes and y pipe, cut out the CATS, put a straight pipe in their place, and getting a quieter muffler from Flowmaster such as their DELTA FLOW which flows better than ANY OTHER brand and isnt as loud as the 80 series.

 

Um, you can't run the stock cats (which are welded into the ypipe) with longtubes.. have you ever noticed the position of the stock cats and where longtube headers end?

You'd have to have a custom ypipe made and a set of aftermarket cats welded in.

Just leave it !cat

 

hrmmmm....good point. looks like I need to go order me some O2 sims !!!!

Actually I never looked that closely, the cars origional exhaust in in pieces. Now that you have enlightened me I have decided the CATS have to go !!!!!

Anyone know where I can get some O2 sims the cheapesT?

 

Hey man.. if u have a 383 you should be getting some programming/tuning done to that car right?

When they are working on the PCM they will be able to turn off your Rear O2 banks, AIR system, & EGR system.

 

well O2 sims cost $100 with shipping. For $75 i can have PCMforless tune my PCM and delete the rear O2's ??
and for the EGR, do I have to remove the EGR or not to disable it ?