Ok, I've seen a couple mentions of gutting your 2nd Cat with a pipe. I just recently started my performance mod adventure and didn't even realize we had two cats on the downpipe.

Anyone have a how to with pics?

Can this cause a CEL?

Do you have to take the exhaust apart?

Does it increase performance noticeably?

Does it change the sound much?... I don't want much more sound from my daily driver.

I just can't afford to go jabbing a pipe in parts without knowing I'm not going to screw something up.

Thanks.

 

I would also like to know this.. Except I'm ok with as much sound as possible lol

 

post #17
https://www.chevyhhr.net/forums/hhr-ss-45/dp-testing-ruthless-pursuit-power-43170/

Can be done without removing the DP

 

I guess I'm still not clear on how you gut the cat though?

Any chance for a step by step video tutorial?

 

I was told to take a 2 3/4 pipe cut to length and tap it in the cat with a hammer. Supposed to tap it right in. Makes it a straight pipe.

Boydie

 

Cool thanks.

So you basically unbolt the exhaust from the 2nd cat, use the 2.75" pipe to remove a core of the 2nd Cat, put the pipe back in and leave it then bolt the exhaust back?

 

Ah ok, so any specific material the pipe needs to be?

 

Or you can get a get a high flow catted zzp down pipe, I have one still in the box....thanks Dave.....

 

Just keep in mind that "gutting a converter" is illegal, and you could fail an emissions inspection and face fines under...

"Section 288 – Enforcement: (b) TAMPERING WITH VEHICLE EMISSION CONTROLS –

(1) Section 203(a)(3) (42 U.S.C. 7522(a)(3)) is amended to read as follows:

'(3)(A) for any person to remove or render inoperative any device or element of design installed on or in a motor vehicle or motor vehicle engine in compliance with regulations under this title prior to its sale and delivery to the ultimate purchaser, or for any person knowingly to remove or render inoperative any such device or element of design after such sale and delivery to the ultimate purchaser; or

'(B) for any person to manufacture or sell, or offer to sell, or install, any part or component intended for use with, or as part of, any motor vehicle or motor vehicle engine, where a principal effect of the part or component is to bypass, defeat, or render inoperative any device or element of design installed on or in a motor vehicle or motor vehicle engine in compliance with regulations under this title, and where the person knows or should know that such part or component is being offered for sale or installed for such use or put to such use."

It's better to look into certified performance converters, such as a unit by ZZP as mentioned above by SS fan.

 

Buzzkill! Lol