Thread: Need advice on a getting a new cat

So I'm new to this forum and I believe I am posting this in the right section. I have a 2001 Grand Prix GT and I believe its a 3.8L v6.

I have been having some issues with my car stuttering while idling and my service engine light flashing. I have had a broken cat for years and it seems to be starting to give me trouble. So I am thinking about getting a new 2" down pipe with cat back from zzp. So here are my questions...

1. Is zzp reliable?
2. What are all the parts i would need to mount the 2" down pipe to the stock manifold and exhaust?
3. Is there any maintenance I have to keep up on if I install the new down pipe?
4. How will it affect my gas mileage?
5. Will it have any adverse affects on my car in a few years?

Thank you in advance!

Take it to the vet.

But seroiusly, go with ZZP. They are good. I would email them for better advice.

You mean 2.5" downpipe?

Howdy 01GT guy:

My wife has a 97 GT, I put a 2.5 inch ZZP 304 stainless pipe with cat on it because I kept getting a P0420 code. The pipe fit with no mods and wife says it made it sound better. Milage has gone up about 1 or 2 MPG.

I was still getting the P0420 code so I did the anti-fouler trick. I had to change the O2 sensor out and used a Bosch replacement because the stock one was to large to fit the anti-fouler. Since then no more P0420 code. The truth of the matter is that the old O2 sensor may have been bad, but everything together works so I am not changing a thing.

With the U-Bend deleat that is part of the new pipe I had to clearance the underside to fit the O2 sensor with the anti-foulers. I just used a bottle jack to dent around the sensor to make it fit.

As far as the ZZP downpipe goes you will not find a better built one IMHO.

Good luck
Robert

Originally Posted by slick2500

If you dont have emissions just put in a piece of strait pipe, and do the non-fouler trick.

I actually totally forgot that I don't even have to do emissions. So should I get or new downpipe or by strait pipe do you just mean I should find a piece of 2"(i believe) pipe and weld it to where I delete the cat. And how exactly does the non-fouler trick work? Also if I should get a new downpipe, is there something that will fit a 2.5" to my 2"(i believe) stock maniifold?