Eric Lai answers readers’ auto questions every week for Wheels.
Q: Is it true that vehicles that failed the previous tailpipe sensor e-test used until December, 2012, might pass the new OBD e-test because it doesn?t check NOx (nitrogen oxide)?levels?
A: Catharine McGregor, government spokesperson for Drive Clean, replies:
This year, like 33 other provinces and states, Ontario has switched from a tailpipe emission test which provided a snapshot reading of several individual pollutants including NOx at a single point in time, to a test that reads emissions control system information recorded by your car?s own internal computer. The new test is faster for motorists to take, gives a more accurate reading of a car?s emissions, takes up less space in the service station, and pinpoints problems to make any needed repairs more effective in reducing pollution.
In short, the new onboard diagnostic (OBD) test provides a more complete test of a vehicle’s emissions systems, and it is better at detecting problems that often lead to a vehicle’s poor performance, high emissions of NOx and other smog-causing pollutants, or poor fuel economy. Based on experience elsewhere, the new OBD test is expected to be 20 per cent more effective in reducing smog-causing pollutants than the previous tailpipe test.
Eric Lai adds:
If your vehicle failed a pre-2013 Drive Clean test because of high nitrogen oxides (NOx), the short answer to your question is yes, it might indeed pass the new e-test.
The new OBD test doesn?t specifically check for NOx. I?ve personally seen a vehicle with a 2012 Drive Clean fail for NOx come back and easily pass the 2013 OBD e-test without having performed any repairs whatsoever.
Regardless of NOx levels, the ?check engine? light can?t be on in the tested vehicle, as this is grounds for an automatic fail under new 2013 Drive Clean regulations.