Do any members have any experience regarding exhaust modifications to a 986 Boxster S ? Namely, the deletion of the factory header/pre-cat set-up in favor of an after market header that utilizes lower cell cats located further "down stream". My understanding is that this would also require the re-postioning of the O2 sensors and re-mapping the ECU as well in order to keep the vehicle OBD compliant. Currently, my vehicle is equipped with a custom cat-back exhaust with the removal/bypassing of the secondary cats and an EVO high flow air intake. So far, I've had great difficulty finding a knowledgeable "tuner", as well as high quality parts to accomplish this project. Some good advice would be greatly appreciated.

Thanks,

Johnny

 

I have Dansk headers (eliminating the pre-cats) on a 2001 S and my mechanic just extended the secondary O2 sensor aft of the remaining cats. I also have the EVO cold-air intake and had the ECU remapped by Powerchip. Great sound, the butt dyno (the only one that matters) says it is faster and more responsive, and no CEL yet - after over 7,000 miles. Passed smog test OK.

 

Thanks for your response. Are you still using the OEM 400 cell secondary cats ?

Thanks,

Johnny

 

Yes - OEM stock cats. My mechanic just installed O2 bungs for the sensors aft of them and extended the lines back.