OBD II and Va. Emissions Inspection

[jwg2]

Took my Z06 in for its first ever Virginia Emissions test this past week. I was puzzled by the fact that the inspector never put the car on the dyno and never put a sniffer in the tail pipe. The only thing he did was plug the testing unit into the OBDII connector under the dash. My test results came back all n/a for HC ppm, CO%, and NO ppm at both 15mph and 25mph, and an official "PASS". I've taken other OBDII cars through inspection and always got sniffed. Turns out Virginia now has a test that uses your stored data to determine if your car is 'clean' More info is here. http://www.deq.state.va.us/mobile/mobobd.html After reading it, it looks like its just checking to see if you've run through a series of use cases the OBDII monitors and if those use cases throw codes. My guess is you could get car with problems through just by resetting your DTCs before you get the car inspected. As an aside, one of the local papers here ran an analysis of all VA emissions inspections on cars 5 years and newer, and found only 0.6% failed (or about 200 cars).