My '92 civic DX hatch just passed barely the emissions test in Ontario. 1st place had my NOx at around 1200ppm versus the limit of around 600ppm. For the 2nd test I used higher octane fuel and ran in higher revs all the way to the test facility. This time I barely passed. All my other numbers were within spec for the HC, CO, etc. My car has 377,000km or 265,000miles. I probably should have done a tune up. Oh well, I'm cheap.