I would go with the OEM one. I changed the one pre-cat with an OEM made by Bosch and it worked like a charm. __________________ custom dual exhaust,M3 front and rear bumper, 10.4 inch roof mount drop screen, Viper alarm system, DSII's rims, M3 Vader Seats, M3 Mirrors, Carbon Fiber CAI, Smoked Corners, Side Markers, Leatherz armrests, black grilles 225k miles and still the Ti goes on |