Gutting the standard cats

[Tim1137]

Originally Posted by Bigsmoothlee

Theres nothing to lose and everything to gain in terms of power when you delete the cats in a boxster. The front Cats are too close to the engine, and the rear cats are at a funny angle.

Last friday, I installed ebay headers, gutted the cats at the mid section, and added a NHP exhaust. No loss of torque anywhere. Feels like I gained between 10-15 hp ( Im running a 911 3.4 engine )

Heres the trick with the rear cats. They're not easy to gut. They're made of foil, and its EXTREMELY difficult to remove all the material. It took me 3 hours per a side, and thats with all the tools in my shop ( Torch, air chisel, long needle nose pliers ).

And, in addition to that, the exhaust gases echo and make a strange sound in the empty cat, so I am going to remove them and install a pipe instead.

Oh, and if you dont flash the ECU to ROW specs, you'll get a CEL. Ive read that Subaru guys install spacers to their rear o2s with a cat delete, and that BMW guys install O2 simulators. So there are 3 options to avoid a CEL

You installed those like 200 dollar ebay headers right? How did you like them? I was looking at them today. Hows the fitment and does it make the exhaust sound raspy?