cat knockout?

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?

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.

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. :)

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

Take It Out You Will Love It!!!

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?

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.

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

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!

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

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.

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.

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!

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

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.

I am lucky, in my area, i do not have inspection. But when the do start it, im gonna put the shell of the cat back on. I save the old one, and gutted the inside. Just cut it in half, slip it over, and weld it to the pipe. They'll never notice

Don't they do emissions tests with the inspections? If they ever start here, I'm getting 2 big cats with Y pipes for each side of the engine. Hopefully, they'll flow enough that they don't cut down on horsepower... I will miss the sound of straight pipes tho :(

yea mn here and no ispections!