I wanna remove the CAT...will it hurt anything? - Diesel Forum

EMIEVEL · 04-21-2003, 05:59 PM

What I want to do is remove the catalytic converter, run 4" pipe with a good muffler, install a TB spacer, and have a custom chip burned to work with all that, plus my K&N II. What do you motor guys think of this? When I did my search, I found out that injectors and intake manifolds differ from year to year, and also CA models from 48 state models. I want more power and torque, like that's never been said here!

I live (sic) in Oregon on a farm, so emission testing doesn't apply. If it did or if any of you are concerned about the air quality up here, I will only use this truck for racing and farm work!
Thanks,
Chris
PS. I need to do these mods fast, so any help...

SD-SDv10 · 04-22-2003, 01:15 AM

Hi Chris,

I haven't done this myself, but the three people I have read about on various message boards who have removed their cats have all put them back on. The OEM cats flow quite nicely and the loss in back pressure usually does more harm than good. The best improvements I have read about involve headers, a new y-pipe and a free flowing exhaust. Check out Stan's website <font color="blue">[link]</font> regarding Borla header install.

Don

EMIEVEL · 04-23-2003, 12:38 AM

Well, I have some experience removing the cat on my 5.0L van. I got better mileage, better throttle response, and more top speed. That particular engine didn't have a sensor after the cat, just before the cat, so the engine light didn't come on because of the exhaust. I have already removed the cat once (on the V10) chasing an engine problem, and I will tell you that it makes a difference. The only reason I re-installed it was because the light came on. I was also under the impression that the computer will lean the mixture to compensate for the rich burn, and I didn't want to hurt anything. I have talked to motor guys that say the back pressure isn't an issue for this application.

What I need to know is, can a custom chip help the lean mixture condition, and does anyone have any suggestions where I should get this done?

Thanks,
Chris

dadomin8r · 04-23-2003, 05:24 PM

What are you pulling it off of? I have a V10 and I tried to run a 3.5" cat back and it flowed too much, I thought. I went back to 3".

Johnny96 · 04-23-2003, 05:55 PM

Yes--it will hurt your wallert when you get arrested--that's a FEDERAL CRIME. Modern catalysts DO NOT COST POWER. Don't even think about this unless it's an off-road only truck & a catalyst is a safety hazard.

EMIEVEL · 04-23-2003, 11:41 PM

You made your point.

EMIEVEL · 04-23-2003, 11:44 PM

[ QUOTE ]
What are you pulling it off of? I have a V10 and I tried to run a 3.5" cat back and it flowed too much, I thought. I went back to 3".

[/ QUOTE ]

I'm pulling it off my dually. Why did you think it flowed too much? Did your mileage or power decrease, or did it make too much noise?
Thanks,
Chris

ohski · 04-24-2003, 02:24 AM

Well forget the TB spacer its a waste of $75-$100... To be honest I don't think removing the cat is going to help either. I would do headers and a Y pipe and a good mandrel bent cat back exhaust system. You might get a few horse out of a chip but don't expect too much there either. I am a bit lost though... you said you live in Oregon but your location under your name is Cali, what gives? Putting your truck info in your sig always helps others when your asking questions.

georger · 04-24-2003, 12:27 PM

[ QUOTE ]
Hi Chris,

I haven't done this myself, but the three people I have read about on various message boards who have removed their cats have all put them back on. The OEM cats flow quite nicely and the loss in back pressure usually does more harm than good. The best improvements I have read about involve headers, a new y-pipe and a free flowing exhaust. Check out Stan's website <font color="blue">[link]</font> regarding Borla header install.

Don

[/ QUOTE ]

Ya, I've also read of guys doin this. Didn't really work out like they planned though. No difference. I would concur w/ don on this. If u want to open her up, headers "w/ y-pipe", cat-back and FIPK or Zoodad. For a chip check on Diablo Delta.

dadomin8r · 04-24-2003, 01:59 PM

Trust me man, you could run a straight pipe off the exhaust and it won't be too loud. The v10's aren't a loud motor. I thought I might have lost a little off the bottom, and maybe a little milage (.2 or so...maybe). PM me if you want to try the 3.5"er. I would have run the 3" spintech but I found the flowmaster laying around and went to town with the welder. To tell you the truth, I only ran the 3.5" to make it loud, as everyone knows, the increase in muffler size won't help you too much if you've got a 3" cat. I only put the 3" on to try to get another half mile/gal out of it. I haven't checked because it doesn't seem to have made enough difference for me to swipe my card twice at the pump and fill it all the way up.

Johnny96 · 04-24-2003, 05:05 PM

[ QUOTE ]
You made your point.

[/ QUOTE ]

Evidently not, since you seem determined to go through with this asinine idea.

WhiteSuperDuty · 04-26-2003, 07:59 PM

[ QUOTE ]
that's a FEDERAL CRIME.

[/ QUOTE ]

Actually it's only a federal offense- not a crime. Anyway, thats not the point- He already stated its for farm use and racing- [img]/ubbthreads/images/graemlins/wink.gif[/img] [img]/ubbthreads/images/graemlins/wink.gif[/img]- When I put on my headers, I ran them open for about a day, and compared to how my exhaust is now, it seemed to have more power. That actually might have been the noise making it seen like it had more power though-

3992824 · 04-26-2003, 10:18 PM

Some folks believe what they want to regardless of fact!

Johnny96 · 04-27-2003, 11:30 AM

I hope he gets caught, and I hope he gets NAILED TO THE WALL for it, and loses everything he owns.

WhiteSuperDuty · 04-27-2003, 05:25 PM

Geez Johnny, that kind of harsh, don't you think?