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