As you know, the 997TT O2 sensors are very to sensitive, and aftermarket exhausts tend to give CEL's. I love the sound and performance of my speed tech 200 cell exhaust. I do get occasional P430 error codes despite adding O2 bung extensions. I keep a small OBD II code reader in the car to reset the error codes when they happen (about once a month - usually when driving hard in sport mode))

I changed my bung extensions to the mini cat CEL fix extensions from big daddies garage and it eliminated my CEL's

The Bung extension has a mini catalytic converter in the unit and it cleans the exhaust gases so that the O2 sensors never pick up unburned gasses.

A product that works as promised.

http://www.bigdaddiesgarage.com/mini-cat-cel-fix.html

 

I thought these looked cool, but I was afraid that they would also alter the real function of the O2 sensor in mixture control.

 

ErSkateDoc - How long have you had the mini cat extension on for? TIA