In Ontario you have to pass Drive Clean to renew your plates. Mine (for the last three times) fails the test (for excess NOx) then I scramble around, try a few things and somehow cajol the technician to complete the test when the exhaust is really warmed up. My brother thinks I have a lazy catelytic converter.
I can't take the stress of scrambling each time.
What can I do (short of replacing the Cat - which I will if I have to), to reduce NOx and pass the first time?
I am due for valve adjustment, I am due for an oil change and I run regular gas.