bad catalytic converter

I've got a 01 v6 tacoma. And my check engine light came on today got it checked and the catalytic converter is bad. Instead of buyin a new one I'm thinkin about just cuttin mine out and puttin a straight piece of pipe in place of it. What do yall think about that? It shouldn't mess anything up right?

 

Bump. I'm also in SC where we have no emission checks

 

Bump

 

My guess is you will not get many answers to this since what you suggest, though I understand some people do it, is a federal crime. Just guessing but they might think that it is not very smart for them to tell you they know how to do it, have done it, or approve of doing it. Again, I do not know--just guessing.

 

Hello I remember this from the other day
http://www.tacomaworld.com/forum/performance-tuning/204645-catalytic-converter-needed.html

you really need to replace it, it will mess with the computer.
I used to have a 2001 mustang gt and did the high flow exhaust upgrade and replaced the factory with high flo cats and did not have a problem.
they are tight up here on emissions, (they dont give a damn if its held together with duct tape) and they would really check the stang but she passed and never fliped a code.

 

I WOULD not put a STRAIGHT PIPE. That's against the law.

 

I had no idea its against the law. but lets say i do it. well we have no emission checks here so my guess is if i were to do it i wouldnt get caught. but why would it mess with my computer. what would be the difference in it not workin or not bein there

 

i don't have one

i don't see it being against the law because my dad had the cat stolen off his truck and he took it to a muffler shop and they welded a straight pipe on it

if it were against the law then i don't think they would have done it, right?

 

Not sure, but the way I understand it is that without the cat the O2 sensor after the cat will not get the correct reading ( because the cat is no there to "filter" the gasses) so it will send the wrong signal to the computer, which in turn will adjust your fuel mixture to less than optimum, which will inturn impact your air/fuel sensor (pre-cat sensor) and you will start to get all kinds of error codes along with potential loss in mpg and power.

Cats are expensive, but I have seen aftermarket ones that are much cheaper than the one at the dealer.

 

Yeah i don't really see it bein against the law either... i could be wrong though. and even if it is illegal honestly nobody with power to do somethin is gonna find out.

 

Post Cat O2 sensor is what is giving a CEL and will continue to after a straight pipe is installed (most likely), there are ways around this for "offroad or racing use" like using spark plug anti-foulers and drill the first one out so the O2 sensor will fit, then screw the O2 sensor into the anti fouler, then screw that into the bung where the O2 sensor was.

Edit: Reason this works, the O2 sensor doesn't "see" as many bad gases NOx I believe. If one anti-fouler isn't enough 2 can be used.

 

If i were to do this do you think i will get awful gas mileage and a loss of power? i really dont want that but i also dont wanna pay for a new cat

 

Pre cat O2 sensor does all the afr, post cat O2 sensor controls the CEL for bad cat.

there are 2 right?

 

The second O2 sensor is only there to monitor the cat. So the CEL being tripped by the absense of a cat will not affect the A/F ratio...the CEL is just annoying.

This can be fixed by using and URD O2 sim. And even aftermarket cats can trip a CEL. Most aftermarket cats are "high flow" and will trip a CEL.

And to the person who said that running w/o a cat is a "federal offense" ....It would be a fixit ticket...and the OP lives in a state where there are no emissions testing...is a LEO going to check under his truck for a cat if he gets pulled over? [No]

 

Most aftermarket cats are "high flow" and will trip a CEL.

Well that is not so. I put in a magnaflow highflo duel exhust system myself on a 2001 Mustang gt in 2004, with 2 new high flo cats, back to shorty headers, and never tripped the puter. went right out two months later and passed the Ill. emissions test. And never had a problem till a drunk driver tried to take us both out.

 

It is required to be on there by law. I think it is against the law to take it off. That said, do not think I ever heard of someone getting arrested for it. It will throw a CEL code, but you can just ignore that. I have heard of people driving cars for YEARS without them. When you go to sell it though, you are probably going to have to come clean and replace it.

Companies in states with emissions testing sometimes pound a straight pipe thru the cat, then replace the cat right before the test.

 

yes...IIRC an exhaust leak can trip a P0420 code. I had a cracked manifold and it was setting off that code.

 

Yeah im startin to think its not the CAT. Ive been told if the CAT went bad i would know it. When the CEL came on the truck ran no different. Everything seems fine and normal

 

Any unusual ticking coming from the engine bay? I had a tick for the longest time that I thought was normal for the 2.7L. Turns out it was a cracked manifold. Replaced that, tick went away, and so did the CEL/P0420 code.