Catalyitc Converter question

[dcbeggs]

I'm not very familiar with the stock MP3 exhaust. Is the catalytic converter pretty much right on the header, followed by a resonator? If not, where is the cat supposed to be located?

The only reason I ask is because I picked my MP3 up with an after market exhaust already on it, and it does not appear to have a cat on it (unless it's right on the header). My exhaust goes from the stock header to a straight pipe to an Apexi muffler.

Anyone know how the stock exhaust looks? Thanks all.

 

[toucci]

there are three main parts:
header/1st cat
midpipe/2nd cat
"cat-back" exhaust

the 2nd cat should be on the pipe that starts at the oilpan and goes back

 

[dcbeggs]

That's what I was thinking, but wasn't sure. I don't have any idea if I'll pass emissions without that second cat. Is it possible to pass emissions without the 2nd cat? I picked the car up from Cali and I'm sure the emissions test there are far more strict than here in Colorado.

Could a car like mine (missing the 2nd cat) pass emissions in Cali? If so, I may have a chance here.

 

[BoostedMP3]

You should be ok with no 2nd cat. The first cat is the one that both 02 sensors are connected to. The 2nd cat has nothing hooked to it to read it. I learned that when i took both off and went with just straight pipe. Most mp3 guys just take the 2nd cat out and put in a midpipe and have no issues with passing emissions.

 

[NJP5Guy]

you could always buy a midpipe with a high-flow cat in it. MAM and wagner sell them. $260-300

 

[dcbeggs]

Good to hear. Thanks all.

 

[AznXstazy]

You should be ok with no 2nd cat. The first cat is the one that both 02 sensors are connected to. The 2nd cat has nothing hooked to it to read it. I learned that when i took both off and went with just straight pipe. Most mp3 guys just take the 2nd cat out and put in a midpipe and have no issues with passing emissions.

do you know if it will pass emissions without the first cat? or does anyone know? i want ot keep the rh exhaust i like the sound of it a bit. but with headers i know that it will get louder.

 

[BoostedMP3]

since both o2 sensors are attached to the first cat, you will have to do what i and the rest of the mp3 guys with no cats do. Get the spark plug non-foulers and bore out one of them. and screw them into where the 2nd o2 sensor would be. then screw the o2 sensor in them; making an extension off of the o2 bung so that the o2 sensor it farther away and not reading the exhaust directly.

 

[BoostedMP3]

by doing that, the check engine light will not come on. So you should be able to pass a obd2 inspection. But if you have the sniffer, and it is hooked to your exhaust, there is probably no way to pass it.

 

[JCell]

headers removed the first cat, if u do this, u will need to do a CEL fix, it's relatively easy

 

[BoostedMP3]

thats what i just told him in the last post; the non-foulers fix. It costs all of $4 instead of that expensive mil eliminator crap that you have to chop up your wiring harness to use.

 

[JCell]

y u get mad?

 

[trbomp5]

thats what i just told him in the last post; the non-foulers fix. It costs all of $4 instead of that expensive mil eliminator crap that you have to chop up your wiring harness to use.

Mil eliminator about $1.50. I use them both though. The anti fouler trick did not totally fix the problem and it kept coming back on and off. With both, no problems!

 

[BoostedMP3]

i've had the non-foulers fix for about 3,000 miles now and not one CEL yet. I'd say thats a perminant fix to me. plus there is no cutting at all. just screw it on and off as needed.