Ebay Headers.. OBX Header Manifold
 

Just ordered me a pair of the OBX Header Manifold and there AMAZING!! Perfect quality welds are all sold and built for a perfect fit. way better then the OEM ones. O2 sensors fit right in. the link it here and half the price as name brand ones.

OBX Header Manfold Fits 99 00 01 02 03 04 Porsche 986 2 5L 2 7L 3 2L Boxster | eBay

I'd be interested in hearing if you had problems passing a smog test as their ad says they are not DOT, SAE or CARB approved (You dont' have to worry about CARB as that's a Calif. thing) but I wonder about the DOT non certification. Not sure if the SAE (Society of Automotive Engineers) non certification affects a smog test.

Yep, have the same, and they're nice. Nice enough for me!

You'll need to trim some thing and might have to re-drill a bolt hole, but for the price, it's pretty good!

It won't be certified for anything!
You remove the first catalytic converters, so you'll need cheaters (90° angled O2 sensor spacers), and you might not pass an emission test!

They sure look nice
 

Any Dyno info on the real gains ??

No noticeable gains with just the headers.
A better sound, lighter, but don't expect high gains.
The primaries are too big for a 2.7 or 2.5.

I have a set as well. Bolted in no mod except a trans line was close so we heat wrapped it . Other manufacturers put a small indent in the pipe but OBX doesn`t. I did`nt like the supplied gaskets. I went with another brand from a jobber. Sounds great. No cel`s either.

When I fitted mine I used the layered gaskets only for them to fail and blow out after a month of running. Fitted the proper single shim type gasket and all good since.

I used OEM gaskets too.