Can someone confirm info on a new cat?

[hockeybawler]

My cat has gone bad on my 04 grand prix. From what I have read, I can get away with a 3" 400 cell cat from zzp and most likely not throw a code. Can anyone confirm that I have understood this correctly?

Car is 04, topswapped, speeddaddy headers with new flexpipe, borla mufflers, and zzp tune. Thanks for the help in advance.

[Explicit_Spade]

When you got the PCM did you choose either option that removed P0420 under the option 4 drop down?

[hockeybawler]

I dont believe I did

[Explicit_Spade]

You'll probably set off that code with a high flow cat. You can go to any auto parts store and pick up a spark plug anti fouler to place between the o2 sensor and the bung to resolve the issue. It's a couple dollar fix that seems to be pretty successful.


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[hockeybawler]

What would you go with if you were in my position? Just a regular store bought one or a high flow cat? Also, is 3" correct or should I go 2.5"?

[REDCRAPGP]

If you have headers then you'll need a 3" cat. Personally I'd either run catless or replace with a high flow cat and have the codes deleted either way


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[Fivefingerdeathpunch]

I don't recall the part number off hand and I'm sure it's changed by now but magnaflow does sell a higher end cat converter that works far better than the high flow cats.

I think they still might call it a high flow converter but it is double the price of the cheaper $50 dollar cats that you can just toss in there.

[hockeybawler]

Will this one work? It doesnt need to be the best, just needs to get me by for the next year or two that I have the car. Thanks guys
http://www.autozone.com/exhaust/cata...ter/34059_0_0/

[willie14]

So what did u do with the speed daddy headers? U had a new flex welded in and then cut a section out to have a catwelded in and its bad already? How long have you had I like that?

[hockeybawler]

With the headers I had the flex cut out and a new one welded in since mine leaked from there just like others who have speed daddy's. I havent done anything with the cat, this is still my stock cat and I have had this combo now for about 4ish years.

[hockeybawler]

So would the one I posted be a decent high flow cat to get me two years of time hopefully?

[willie14]

I'm still runnin my SD headers with no leaks yet, SD flex and only used bandclamps on the 3 in DP the rest has just better U bolt style clamps..no rtv on nothing my slip joints were super tight so I didn't see the need to use it