Before 2nd O2 sensor and stock air box installed: (had a short ram intake) Failed HC 1.4 >>>>> limit .6 Failed CO 16.8>>>>>limit 10.00 Passed NOx 1.03 >>>limit 1.5 After 2nd O2 sensor+stock airbox installed: (bastards won't test my car cuz of the short ram intake) Failed HC 1.3 Failed CO 13.55 Failed NOx 2.08 HC and CO seem to dropped a bit, but NOx almost doubled. Did research and the cause of failure for HC + CO is most likely because the car is running too RICH. Too advanced of a timing and ignition related. NOx = High combustion temperature + running too LEAN How could this be? Running too RICH + too LEAN @ the same time isn't possible... CAT should be working fine. Got it put in a couple months ago. Anyone know where the EGR valve is located on a B16a2? Thanks!