What year is your car? The 94-95 has the O2 sensor in the collector area of the header. The 96-01 has 2 O2 sensors...one in the collector area of the header, the other in the rear portion of the catalytic converter.
__________________
2015 Ford Mustang GT Fastback - Ingot Silver - 6M - Performance Package - Gibson Catback, JLT CAI, FR 47lb injectors, BAMA E85 tune, Eibach Sportline, BMR wheel hop kit, UPR oil separator, Steeda shifter bushing/bracket
Team B.O.B.® - Ballaz on a Budget