therobman7

i got a buddy who just hollowed out his cats.... seemed to work pretty well, but not sure how it would affect performance

androdz

Incorrect completely the Magnuson-Moss act states that the only reasons a dealer can deny your warranty is A. because they can prove that the modification that you made to your car is the reason why your car failed or B. Your car no longer meets EPA requirements on emissions.

http://forums.genvibe.com/zerothread?id=101
http://www.alternativeauto.com/water.../warranty.html
http://www.impalaclub.com/naisso/magmoss.htm
http://www.enjoythedrive.com/content/?id=8123
http://www.enjoythedrive.com/content/?ID=8124
http://www.ftc.gov/bcp/conline/pubs/...#Magnuson-Moss

Att. Andrew

Commodore

There used to be converter bypass pipes available some years ago for "testing purposes only" that were forced off the market by the Fed. Modern converters are much more efficient than they used to be. A GT-500 moves a lot of exhaust through its converters and makes big power. Without them (even if you could easily gut them to pass a visual inspection) you will fail an emission test. You will need to reprogram your ECU because your exhaust back pressure will change affecting all kinds of fun stuff. The sound of your exhaust will be a bit louder but not as much as you might expect. Say goodbye to any warranty you have and also risk losing your registration until the vehicle is proved to be back in compliance. Still want to 86 your cats?
RB

MusiccityGT

Zcat, you can use the diablo to disable the rear o2 sensors. The MIL eliminators plug into the harness' in place of the o2 sensors and trick the ECC into thinking they are there, hence not throwing a check engine light. With the high flows you have, you will likely see very little gain. Not worth the trouble IMO. With your current lean condition during open loop, I would be leary of eliminating the rears to possibly allow a lean condition in closed loop.

zcat

Roger that Musiccity - I will be correcting the lean condition 1st. If the cats come out, it will more than likely be because I drag them so easily and I believe they'll keep dragging till they're damaged. I've heard that the ceramic inside can break up causing blockage in the exhaust - that could be a little detrimental to engine life[:-]

Bayouboy4.6

so are you saying that the car will run lean?

vsop

Its simple I ran over a a rock in the road and it cracked my cat so I had to replace my stock pipe..

Also down here in FL, dealers really don't care about the cats as there is no inspection or emissions testing. So its a common mod