For everyone with a tune and cat bypass pipes:

Were you required to install O2 extenders for the rear O2 sensors (effectively taking them out of the direct exhaust stream), or was this accounted for in your tune?

Did your tune turn off the CEL completely, or was the threshold widened so it would not trip the check engine light?

Is there any downside to having that CEL removed from the tune so it never goes on? Are there any other functions that require the use of the rear O2 sensors or are they only to check the function and performances of the catalytic converters?

 

It depends if you are subject to catalytic readiness checks or not. If you turn the CELs of in the tune you wont pass inspection via the obd2 port.

I am adding the FVD's extenders since I need to pass this every year (and I dont want to change back to stock exhaust and drive around to get readiness)

 

I'm not worried about the emission requirement angle at all. I only swap out the pipes for offroad use. I use cats on the road.

However I do not want to see the light tripped when driving on the track.

 

No need for the extenders with a tune.

 

Then just have them turned off in your tune!

 

I asked for that, but they are saying that turning the CEL off affects other protection functions the ECU uses to safely manage the engine and it's the wrong thing to do.

I'm getting pretty frustrated by the refusal to fix it in the tune to be honest.

The tune does works flawlessly otherwise however.

 

Actually there must have been a disconnect because I just hung up the with the tuner and he is going to give me a file removing the CEL for when I'm at the track.

 

So if you have cat-less with extenders you can pass inspection?? without a tune? understand you will not pass a visual look.

 

I'm getting pretty frustrated by the refusal to fix it in the tune to be honest.

 

Change tune, I have Cobb and there is no issues to get a track tune wo CELs.

 

I run the stock cats on the street so it's never been an issue with the CEL or inspection.

I remove the cats for track weekends.


It turns out it was a misunderstanding on my part.

The tuner is taking care of it with a track only tune option. I'll switch back to the street tune when I put the cats back on.