Remove cat.

**bowtechguy** · 06-03-2009

Hey all, ever since I had a missfire n ran my car for a couple days that way my Cat. has been stinking and now I'm getting a slight rough idle. So I was wondering, what will it hurt to cut the Cat. out and run a straight pipe in its place? Would it mess with the O2 sencor behind it?

**Scimmia** · 06-03-2009

You would need to get an O2 sim or get the computer reprogrammed to not report the cat codes.

**bowtechguy** · 06-03-2009

An O2 sim, forgive me but whats that?

**bowtechguy** · 06-03-2009

Sry i looked it up, o2 simulator . got it now.

**Scimmia** · 06-03-2009

yeah, sorry, it's O2 simulator, sometimes I type in shorthand too much. ZZPerformance and WBodyStore both sell them, I believe. I got one from ZZP I've been meaning to pull since I got a tuner, just haven't gotten around to it.

I believe there's even a way to accomplish it with a simple resistor, but I've never tried that.

**Bio248** · 06-03-2009

Originally Posted by Scimmia

I believe there's even a way to accomplish it with a simple resistor, but I've never tried that.

that doesnt work because it wouldnt be able to mimic a wave. its not just a steady voltage that it wants to see.

**Scimmia** · 06-03-2009

Originally Posted by Bio248

that doesnt work because it wouldnt be able to mimic a wave. its not just a steady voltage that it wants to see.

Yeah, I've heard that, but I've also heard people claim success with it. I wouldn't think it would be reliable, but the sims aren't exactly reliable, either, they tend to go bad after a while. Tuner FTW!

**bowtechguy** · 06-03-2009

So its best to leave the O2 secsor if I take out the Cat.
Hopefully soon I can get a new Cat. anyway.
Thanks

**Scimmia** · 06-03-2009

If you leave the sensor in, you'll throw a code and the check engine light would come on. I guess if that's not a problem for you, then yeah, you'd be fine.

**Bio248** · 06-03-2009

Originally Posted by Scimmia

Yeah, I've heard that, but I've also heard people claim success with it. I wouldn't think it would be reliable, but the sims aren't exactly reliable, either, they tend to go bad after a while. Tuner FTW!

yeah, my sim started being intermittent so i just put the sensor back in since i still have a cat anyway.

**blueguy** · 06-03-2009

Just cut it out and live wih the code

**Scimmia** · 06-03-2009

Originally Posted by bluegtp91

Just cut it out and live wih the code

And hope nothing else goes wrong, since you might not know right away since the light is already on.

**blueguy** · 06-03-2009

Originally Posted by Scimmia

And hope nothing else goes wrong, since you might not know right away since the light is already on.

The :P Smiley meant a joke

**Scimmia** · 06-03-2009

Originally Posted by bluegtp91

The :P Smiley meant a joke

lol, I replied too quickly, must have missed that. There's actually a lot of people who do just that, my dad's even driving around with the MIL on because of an EVAP problem we've never completely tracked down.