tritonofg

I have a 97 Cobra that I cannot seem to get to pass smog in CA. My NO (NOx) numbers are really high. I have a chip in the Car with a tune (Powertrain Dynamics EEC-V Dyno Chip). I called them up and they stated that the tune was set with a 12.8 A/F mixture (Rich). I have checked the PCV valve and it works. I do not have my check engine light on so I am asming that my EGR Valve is working and my O2's are too (anyone know how to check this)?. The only mod that I can think of that is causing my elevated NOx levels is my Bassani Catted X-pipe. I have a line on a 01 Cobra H-pipe. Will it fit on a 97 cobra or are the bolt pattern and mounting poits different? I need a stock one to pass the visual inspection.[/align]

tbirdscwd

The bassani pipe is almost definitely why you aren't passing. The bassani pipe only has 2 cats, which won't run as clean as your stock pipe with 4. Unless your tuner messed with the timing in the low rpm range, chip shouldn't affect it because the 12.8 a/f will only be at WOT (which it will never see during the test). I would just pull it anyways just to be safe. At partial throttle your 02 sensors will keep it at 14.7-14.9 a/f. I'm not sure about fitment on the pipe. Try to get your hands on a stock H-pipe. You might be able to get the 01 pipe to fit, but everywhere I've looked, they use different pipes from 96-98 and 99-04.