My 1990 CRX just failed smog here in CA. Everything passed except NO(PPM). It was almost double what it was supposed to be. I suspect EGR first. Does anyone know how to test these? Its a 1.5 with DPI throttle body. I have 10 days to retest or i lose the $40 i paid for original test. The car is all stock and has 88,000 miles. And never overheats. Always runs under halfway on Temp gauge. Thanks alot.