Remove Gen II Cats... Effect on Oxygen Sensor?

[georgethedog]

If I replace my stock cats with a straigt pipe (off road use of course) and keep the rest of the exhaust stock (trying to save $$$ right now but get rid of the heat), what will be the reaction of the oxygen sensor that is located right after the stock resonator?

I don't want the car to either run poorly and/or have that damn check engine light on forever. Any tips out there? (It's a 2001 if that makes a difference) Thanks.

 

[uvbnbit]

My CEL came on after about 300 miles. Reset it and it didn't come on again. You can also put sims or tie it up out of the way. The rear (downstream) O2 is to check and make sure the cats are functioning properly. I don't think it has anything to do with tuning. You will get rid of a lot of heat, but you may increase an exhaust fume smell.

 

[georgethedog]

Thanks. I did a search on the site and found a discussion about the simulator. I'm gonna price some high-flow cats from JonB then make a decision. Thanks.

 

[red heat]

I replaced my catalytic converters with hi flo cats from roe racing. side sills much cooler. no check engine lights on and they have been in for about 1 yr. hopefully my 02 RT will pass emissions when the time comes.

if you by hi flow cats, consider getting thermal wrap with them as well

 

[dave6666]

I have high flow cats, no wrap, and no sill heat other than what living in Texas provides you in August.

Do your research on wrapping the cats. You may be fixing one thing at the expense of another.

 

[georgethedog]

I replaced my catalytic converters with hi flo cats from roe racing. side sills much cooler. no check engine lights on and they have been in for about 1 yr. hopefully my 02 RT will pass emissions when the time comes.

if you by hi flow cats, consider getting thermal wrap with them as well

So, you kept everything else stock, right? What difference did it make in sound?

 

[georgethedog]

I have high flow cats, no wrap, and no sill heat other than what living in Texas provides you in August.

And May, and June, and July... Anyway, thanks Dave for your comments. I think air is the best friend, so I'm not real keen on the wrap.

 

[georgethedog]

I replaced my catalytic converters with hi flo cats from roe racing. side sills much cooler. no check engine lights on and they have been in for about 1 yr. hopefully my 02 RT will pass emissions when the time comes.

if you by hi flow cats, consider getting thermal wrap with them as well

Thanks Red Heat. Why the thermal wrap?

 

[Tom F&L GoR]

My CEL came on after about 300 miles. Reset it and it didn't come on again. You can also put sims or tie it up out of the way. The rear (downstream) O2 is to check and make sure the cats are functioning properly. I don't think it has anything to do with tuning. You will get rid of a lot of heat, but you may increase an exhaust fume smell.

The way the system is supposed to work, the CEL should come on if the downstream O2 sensors don't signal that the oxygen level varies in some relationship (and not 1:1) to the upstream signal. You can reset it, but should come on again and again. I guess this isn't always true. The engine operation should be unaffected. Lots of "supposed to" and "should"...

 

[red heat]

with the high flo cats the sound of the car is slightly louder (better sounding). you will gain 20-30 HP as well. everything else on the exhaust remains completely stock. the high flo cats are considerably smaller in caliber than the flo restricting stock ones. the thermal wrap was only a few hundred dollars more and fits easily underneath the side sill. in addition, you can still keep on that cheap ass aluminum half wrap that came stock with the car.

I have already painted the side sills twice because of the excessive heat from the stock cats. for a little extra money, adding the thermal wrap is some added insurance. the wrap is supposed to withstand up to 1200 F.

 

[JonB]

I agree with a lot of the above, except:

1) NO HF CAT will give you +20 - +30HP !!! Aint No Way, unless your prior cats were dynoed when clogged and you were losing 15-20HP......

2) DONT wrap your VIPER exhaust. For several serchable reasons.

 

[Camfab]

I agree with a lot of the above, except:

1) NO HF CAT will give you +20 - +30HP !!! Aint No Way, unless your prior cats were dynoed when clogged and you were losing 15-20HP......

2) DONT wrap your VIPER exhaust. For several serchable reasons.

Agreed 100% on this. The factory shielding is not Aluminum, it's stainless.

 

[plumcrazy]

Whay Jon said

Use simms or a plug non fouler to set the sensor deeper up into the pipe. I passed ins with it.