Question about Cats

Reply Subscribe

Thread Tools

Search this Thread

Jul 20, 2010 | 06:28 PM

darkmage55

Thread Starter

Senior User

Joined: Sep 2009

Posts: 153

Likes: 0

Question about Cats

Im planning on replacing my cats with some high flow ones here in the near future to get a nice sound out of my truck... the muffler being cut off just aint doin it for me lol. My question is do i have to get all 4 high flow cats for the front ones and the back ones? Or will just replacing the most rear cats do? I heard once that the front 2 cats arent really cats... but im not sure. Please help and thanks.

Jul 22, 2010 | 03:05 PM

1Aauto

Former Vendor

Joined: Mar 2009

Posts: 8,098

Likes: 10

From: Westford, MA

By law from what I've heard is that your suppose to replace what the factory put on,but people usually just toss two on and it takes care of the emissions ok.

Jul 22, 2010 | 05:46 PM

phil6608

Post Fiend

Joined: Jan 2007

Posts: 18,157

Likes: 0

From: Stanton DE

By law ,hes right!
But I took off all 4 and replaced with just 2 high flow cats.
But you better be prepared to buy a muffler! It will be very loud without one or two if you have duals.

Jul 22, 2010 | 07:03 PM

KhanTyranitar

Postmaster

Joined: Oct 2009

Posts: 3,432

Likes: 7

The catch is that most the cats you can buy, even if they are performance brand names, are not high flow cats. If is has a 400 cpi ceramic catalyst substrate, its not high flow.

Jul 22, 2010 | 07:41 PM

BURNSTOUGHFORD

Posting Guru

Joined: May 2006

Posts: 2,486

Likes: 0

From: Iowa

I recently put an OBX LT system on that removed all 4 of my cats and replaced with 2 resonators.

Before my truck was a stock exhaust with catback and flowmaster 50 series muffler.

With the cats gone my truck is way to loud. It was perfect before, no drone but barked loud when i stood on it. Now its loud all the time and Is obnoxious when i stand on it.

Just so you know, the cats do help quite down the truck. If you want obnoxious all the time then by all means get rid of them and dont put any back.

Dont worry about people who get technical about the law, everyone breaks it. Speeding, late registration. Whos to judge what crime is worse. Guys just pride them selves by pointing out others faults when given the opportunity on this site it seems. To each his own is the way i feel.