Cat bypass with resonator

[gsy4771]

Originally Posted by Dave80GTSi

I'll assume that this is directed to me, since I posted the pictures?

If so, then yes, I've been very pleased with the stock non-cat manifolds and the Circuit Werks "resonators". Aside from the fact that all of the white insulation which was a part of the "resonator" portion of the Circuit Werks pipes was blown out after about the first 10 minutes of use, ending up in the muffler!

Fortunately I was able to fish out most of this insulation after removing the muffler - what I could not remove eventually blew out of the muffler's tips.

One difference between the older pictures that I posted and the car as it sits today is that I ceramic coated the manifolds, as you can see below:



The use of the non-cat OEM manifolds resulted in a notable performance boost as compared to the cat manifolds as shown in the second picture in Post no. 23, so I am well pleased.

DM

Thank you for the response. How you had issues with the car passing inspection? You do not have any cats with your setup? Also any warning lights?

[Dave80GTSi]

Originally Posted by gsy4771

Thank you for the response. How you had issues with the car passing inspection? You do not have any cats with your setup? Also any warning lights?

No inspections required in my county, no warning lights, no worries whatsoever!

[flmont]

Hmm , So for those of us who have to do emissions testing Via the plug under the dash,.and the 2002 manifolds have the 02 sensor B4 the cat, could you backdate to 1999 manifolds or header's and still pass emissions ,if you welded a bung into the Exhaust header,..?? for the 02 sensor..? Thanks frank

[Dave80GTSi]

Originally Posted by flmont

Hmm , So for those of us who have to do emissions testing Via the plug under the dash,.and the 2002 manifolds have the 02 sensor B4 the cat, could you backdate to 1999 manifolds or header's and still pass emissions ,if you welded a bung into the Exhaust header,..?? for the 02 sensor..? Thanks frank

Take a look at my second picture in Post no. 20 of this thread.

You can see that these manifolds do not contain an O2 bung, but there is one at the front of the Circuit Werks resonators.

You need to fab up a pair of cable extensions for the FRONT O2 sensor so that it can reach the shown CW bung. A 'Search' of this forum will bring forth discussions about how to make these extensions.

Finally, you need to do a ROW tune which ignores the presence of the REAR O2 sensor since this system does not require the use of these second sensors. Thus, no dashboard warning lights.

DM

[flmont]

Ah ok..great I have the mid pipes installed and I do have those bung's..so just extend the harness and find some header's ! would the softtronics tune be the same as the ROW tune.? Thanks again,.. Frank

[Dave80GTSi]

Originally Posted by flmont

would the softtronics tune be the same as the ROW tune.

No idea, I'm not familiar with that.

Likely others here who are can chime in.

[flmont]

Thanks Dave...what did you do for your ROW tune.??

[edc]

Originally Posted by Dave80GTSi

Take a look at my second picture in Post no. 20 of this thread.

You can see that these manifolds do not contain an O2 bung, but there is one at the front of the Circuit Werks resonators.

You need to fab up a pair of cable extensions for the FRONT O2 sensor so that it can reach the shown CW bung. A 'Search' of this forum will bring forth discussions about how to make these extensions.

Finally, you need to do a ROW tune which ignores the presence of the REAR O2 sensor since this system does not require the use of these second sensors. Thus, no dashboard warning lights.

DM

For what it's worth the ROW tube does monitor the rear lambdas. I know because when you add sports cats you often get the cat efficiency CEL code. You can right angle space the rear lambda or have it coded out.

[pilot4fn]

Originally Posted by edc

You can right angle space the rear lambda...

What this "You can right angle space the rear lambda" means?

[ike84]

Originally Posted by edc

For what it's worth the ROW tube does monitor the rear lambdas. I know because when you add sports cats you often get the cat efficiency CEL code. You can right angle space the rear lambda or have it coded out.

This is incorrect. Sorry.

Sent from my SM-G970U1 using Tapatalk

[Dave80GTSi]

Originally Posted by ike84

This is incorrect. Sorry.

Yes, I agree. With my ROW tune, I have only one O2 sensor per engine bank, with no error codes whatsoever (as I have already repeatedly noted in this thread).