Ok just went for smog check. I have a 95 civic si. Its a cali model and the ONLY mod is a tenzo exhaust. Could this be the reason I failed? The car runs excellent and has no mechanical problems so im thinking the exhaust is the only thing that it could be. Correct me if im wrong or please add any input on what else it could it be. Id rather handle it now instead of going to a repair place to charge me 150 to tell me whats wrong. Oh btw I failed the emissions part only and only on the 15mph part. I passed the 25 mph. Thanks.