Hi Guys,

Anybody know if the APR flash makes the Cat sensor read "unsupported" or "not ready" in stock mode?

I have a 2006 A3 2.0T with APR stg2 flash, with Stock, 93oct, and 100oct. I have a 3" downpipe with originally no cat, but have cut and welded in a 3" High Flow cat. No Check Engine light, but when I went to NJ inspection in stock mode, they failed me for "unable to determine if a Cat was present".

I have since plugged in a code reader and it shows "unsupported" for the Catalytic category. Is this because of my "rigged" down pipe or the APR flash?

My original downpipe went bad (original cat broke apart), so I can't stick it back in and use it.

If it is because of my downpipe, does anybody have suggestions on aftermarket or used downpipes that will fix my catalytic issue?

Thank you,
Todd