Removing catalytic converters
Thread Starter
Intermediate
Joined: Jun 2009
Posts: 33
Likes: 1
From: Marana Arizona
Removing catalytic converters
I'm thinking of removing my catalytic from the exhaust. What could be some of the side effects to the system. Zip or one of them sells some new oxygen sensors that tricks the computer into thinking their still in the system. Has any body else done this mod and can give me some input?
Thread Starter
Intermediate
Joined: Jun 2009
Posts: 33
Likes: 1
From: Marana Arizona
I make long drives six hours or better regularly with it. Through the desert mostly. I get a lot of heat coming up through the tunnel area because of the converters. I want to eliminate the heat issue.
Le Mans Master
Joined: Dec 2005
Posts: 8,561
Likes: 944
From: Communist Colorado
Well, if you want to keep setting codes on the DIC, have terrible exhaust fumes actually come into the vehicle, like loud occasional backfires and want it to sound like a dump truck on deceleration, then by all means, remove the cats. 
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Insulate the tunnel and floor boards with Frost King heat duct insulation and some reflectex foil covered bubble wrap and you will be amazed at the difference in heat rejection and less road noise:
Installation is fairly easy
BC
Installation is fairly easy
BC
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Instructor
Joined: Jul 2000
Posts: 163
Likes: 0
From: AL
I did a similar mod, replacing my old cats (they ummm, got a hole in them
both) with high flow cats, with the option of off road pipes (no cats) I also had dyno runs done, O2 simulators added and tuning. for the effort, there was a negligible increase in HP and torque with the off road pipes installed. Went back to the high flow cats. All in all, wasn't really with it.
Just my two cents
both) with high flow cats, with the option of off road pipes (no cats) I also had dyno runs done, O2 simulators added and tuning. for the effort, there was a negligible increase in HP and torque with the off road pipes installed. Went back to the high flow cats. All in all, wasn't really with it. Just my two cents
Instructor
Joined: Aug 2009
Posts: 105
Likes: 1
From: Fairfield Ca
cat removal
good thing is that your rpms might climb alittle faster which is good for an all out racer, but for a stock daily driver, there are much more negatives to it. You're going to get alot of popping and burbling upon deceleration, along with the increase smell of exhaust fumes. Not really good to be sitting in traffic on a hot day and smelling that. Why not just get high flow cats?
Drifting
Joined: May 2005
Posts: 1,590
Likes: 1
From: Littleton Colorado
A ceramic coated tunnel plate will reduce the heat, and it will add a lot of stiffness to your Vette. Its a good upgrade. It will not completely eliminate it, but you can follow Bill's post and combine that with the tunnel plate to really reduce heat and noise.
Drifting
Joined: Dec 2006
Posts: 1,523
Likes: 5
From: Holly, Michigan
I had mine removed when the long tubes were installed...Don't miss them. The high flow units are expensive and not worth the bother, in my opinion. Exhaust sounds great without 'em and the smell isn't bad as people suggest...Frankly, it just smells a little rich is all..(and my nose is more sensitive than most)...
Racer
Joined: May 2009
Posts: 263
Likes: 1
From: Andover KS
My cats were removed before I got the car and it runs and sounds OK. It does seem a little rich on the exhaust smell and I don't think there is a measureable power gain without them. I'm with the majority on this one, leave them unless you are replacing the whole system with headers etc.
Burning Brakes
Joined: Oct 2007
Posts: 1,093
Likes: 33
From: Morristown TN
I have no cats on mine and do not notice any smell, I also do not hear and backfires or anything.
Longtube headers, no cats, and Borla Quad tip Stingers and it sounds great.
Just have a tuner turn off the DIC codes for the rear O2's.
Longtube headers, no cats, and Borla Quad tip Stingers and it sounds great.
Just have a tuner turn off the DIC codes for the rear O2's.
Drifting
Joined: Jan 2005
Posts: 1,517
Likes: 0
I don't have cats, but I also dont' have those issues. Had I not been putting on headers, I would have left mine alone, they do serve a purpose, none of of which are to stop exhaust fumes from entering the car or prevent backfires. Your cats could be clogged if they're getting super hot, but the car will pop a CEL if it gets hot enough. I'd try the insulation first and a tunnel plate... My tunnel still gets plenty warm on long trips without the cats.
Instructor
Joined: May 2009
Posts: 141
Likes: 0
From: Alexandria Virginia
Are you talking about a burning type smell after flooring it? I guess I read it wrong, the smell is only if the cats are removed.... meh, guess I have some other problem. I think something might be touching the exhaust.
Didn't mean to thread-jack :P
Didn't mean to thread-jack :P
Last edited by Thalomos; Aug 21, 2009 at 11:30 PM.