Best replacement cat?

[nwilson44]

So a guy at the exhaust shop told me that the California approved cats provide more power than the 49 state cats. What is the best cat I can use as far as power is concerned? I want the most power, Im not too concerned with emissions. Is he telling the truth?

[ssms5411]

Re: Best replacement cat?

I would say it B.S. Cali has the most strict emissions. If your not worried about emissions just straight pipe it and have the code tuned out.

[techsan23]

Re: Best replacement cat?

Or replace it with a resonator.

[nascar24jd]

I agree with the BS call.

Get a high flow Cat or delete it.

[nwilson44]

Re: Best replacement cat?

Thats what I want to do but i think my car is a California car... So i think my computer might be tuned to accept a cali cat. Will the hypertech fix that? or do I need another tune? or Have GM erase that?

[ssms5411]

Re: Best replacement cat?

Hypertech won't do anything, you could have PCM4less or someplace delete the code if your not worried about emissions then run what you want. Also theirs no such thing as Cali tunning it to run on a certain CAT, its just 50 state legal cat ,no more programing than a regular car if its from Cali or not.

[nwilson44]

Re: Best replacement cat?

Yeah how do I delete the cat and tell the computer that its deleted? Will this increase performance or decrease performance?

[Hib Halverson]

Re: Best replacement cat?

On a stock or near stock engine, cat removal may result in a small change in performance.

Even if your car has California emissions, the "tuning" in the ECM, while it may be specific to a CA car, is not going to "care" whether the replacement cat is CA-approved or not. You only need to worry about that if the car is registered in California.

If an exhaust shop told you California cats make more power, he's either misinformed or blowing smoke up your butt. There will be little or no difference in performance of a CA-approved cat and a 49-state cat and, if there is, the 49-state cat will be better.

As for altering the calibration to prevent any "cat efficiency" codes from setting, know that doing so is a violation of Federal law so, to stay legal, you can only do that for racing or other off-road use. Someone who knows calibration has to go in and select "error mode 3" (no error reported) for the diagnostic tests related to the cat along with those related to the rear O2S.

You might think twice about doing that because the cost of having some aftermarket cal guy change your programming might exceed the cost of putting a new cat on the car.

A great replacement cat which is bigger in diameter and is low restriction is the Magnaflow 40006. I replaced the stock cat on my '01 with that unit and a bigger S-pipe and saw about 5-hp at the wheels. Now...part of that is from the bigger S-pipe, but that big Magnaflow cat, at the least, had no negative effect on performance. I believe the OE application for the 40006 is a front-drive V8 Cadillac. I bought my Magnaflow cat on Amazon and it was pretty reasonable.

[nwilson44]

Re: Best replacement cat?

Okay that clears that up. Last couple of questions on this issue. If I buy the the pacesetters will they come with new gaskets between the y pipe and header? And which universal cat will fit on the pacesetter y pipe? My car is a 2001

[nwilson44]

Re: Best replacement cat?

And thanks for the help.

[techsan23]

Re: Best replacement cat?

A 3" cat will clamp to the pacesetter Y-pipe.

[Hib Halverson]

Re: Best replacement cat?

Okay that clears that up. Last couple of questions on this issue. If I buy the the pacesetters will they come with new gaskets between the y pipe and header? And which universal cat will fit on the pacesetter y pipe? My car is a 2001

I don't know how Pacesetter sells their headersets nor do I know the O.D. of the outlet pipe.

My suggestion would be to contact Pacesetter by phone or email and ask them if you get two gaskets. Also, ask them the OD of the outlet. Then, look for a cat which will fit that pipe size.

[fbodyrs96]

Re: Best replacement cat?

The pacesetter gaskets are garbage, you will won't to get some good oe replacements.

[ssms5411]

Re: Best replacement cat?

Yes the Pacesetters are garbage pick up some Felpros.

[nwilson44]

Re: Best replacement cat?

Yes the Pacesetters are garbage pick up some Felpros.

Do I have to get that from the dealer or does like O'reilly or autozone have them? And what Cat do I buy to fit the Pacesetter y-pipe?