KEVINS800

any problems if a guy knocks out the cat on a 94 chevy 350? is it a plus or a waste of time? i have a 2 post lift so it would be easy, i've done it on my older fords and it really seemed to up the hp and mpg. will this help the 350 tbi?

Silverado Brethern

It'll help flow and therefore horse power a lil bit. but not worth it at all for a vortec engine, kills power. i doubt a 95 is vortec but anyway it may throw the cpu off cuz of o2 sensors.

__________________
"Never under estimate the power of stupid people in large groups."

1997 K-1500 Silverado Vortec 350...125,610 and wounded
HD chassis package
Custom TRUE DUAL exhaust with cut-outs and Flowmaster 40 series mufflers
Poweraid Throttle Body Spacer
Custom Ram-air Intake with K&N FIPK GEN II
TFES Performance 3" Suspension Lift
Dual Air-Horn Kit with Compressor
Bed-Mounted 48" Hi-Lift Jack
Cobra Laser Radar Detector
285/75/R16 Cooper Discoverer STT's

1/4 Mile 10/15/05: 16.43 @ 91mph

profox02

Ive Got A '94 Silverado Z71..WITH TBI 350..I CUT OUT THE CAT...THE TRUCK RUNS BETTER, AND SOUNDS ALOT BETTER...DOSNT SEEM TO HAVE APROBLEM WITH BACK PRESSURE.

profox02

My Truck's O2 Sensors R All Before The Cat..so I Dont Get Any Problem Codes

broughy84

Take It Out You Will Love It!!!

__________________
Matthew Brough
1998 Chevrolet Venture -- 104,000 miles
1988 Chevrolet Silverado -- 156,000 miles
1996 Chevrolet Cheyenne -- 107,000 miles

firebird0095

I have a 98 - and I am getting a trouble code saying that one of my cats is bad - there is an o2 sensor behind the cat - is there any way that I can just get rid of them or am I stuck with cats bacause of those rear o2 sensors?

BobM46128

Firebird0095, you can buy "similators" from Jegs, Summit and others that will tell the 'puter that everything is all right. I think they are about $80-90 for 2 of them. I don't know what "cleaning" the cats will do to mileage and power. If you clean yours out, let me know what happens. I'm thinking about doing it to my '98 Express.

sitdusa

I knocked out my cats and put in the O2 sims, runs better, sounds meaner, and no problems

KEVINS800

thanks guys your help is appreciated, thanks again! I'm thinking that after i rebuild my tbi, i'm gonna knock that thing out, and reweld the pipe!

Chevy-SS

Are you guys cleaning out the guts of the converter and leaving it so it appears to be intact when visibly inspected? How does this mod affect emissions testing? Does it help mileage?

Thanks

Silverado Brethern

Whats this here o2 simulator you speak of? how much might one of them cost? and guys that are doing this what year is ur truck? cuz i heard that vortec's (96+) need the backpressure from the cats to run right.

__________________
"Never under estimate the power of stupid people in large groups."

1997 K-1500 Silverado Vortec 350...125,610 and wounded
HD chassis package
Custom TRUE DUAL exhaust with cut-outs and Flowmaster 40 series mufflers
Poweraid Throttle Body Spacer
Custom Ram-air Intake with K&N FIPK GEN II
TFES Performance 3" Suspension Lift
Dual Air-Horn Kit with Compressor
Bed-Mounted 48" Hi-Lift Jack
Cobra Laser Radar Detector
285/75/R16 Cooper Discoverer STT's

1/4 Mile 10/15/05: 16.43 @ 91mph

stratman440

I just knocked out the cat on my '94, and I solved the problem of my hesitation/poor gas mileage. Just go to your local autozone, buy 3 inch pipe and two clamps, and have at it. When you are done, get it welded at a muffler shop for cheap. Mine sounds great now.

KEVINS800

well i knocked her out! looks orginal but she's empty! noticed that the power has increased, but i have not rode tested it yet!

Chevy-SS

How can you pass inspection if you have no visible cat?

J-Ri

They knock out the internal components so it looks like there is a cat there, but it's hollow. Remember cherry bomb mufflers? Same idea, but no explosives

Also, many states do not have any inspection. I live in Iowa and there's no inspections here. I'd have to practically replace the ENTIRE emissions system.

__________________
'04 Cavalier coupe M/T 2.2 Ecotec
Supercharged 14 PSI boost, charge air cooler, 42# injectors
Tuned with HP Tuners
http://www.boycottpepsico.com/default.aspx

So I go to this get-together at a friends house, not remembering it's a few days before Halloween. I see a bunch of dirty looking strangers. Then I see a guy that was clearly wearing a Halloween costume and I make the connection, and say "Oh yeah, Halloween... y'all goin' as a group of bums?". Turns out they weren't wearing costumes.