How do I lower my NOx numbers to pass inspection?

I'm way over the legal limit on NOx and i've already got a new catalytic converter, tuned up, and cleaned my EGR valve. I don't know what else to do. I need to pass soon, please help?How do I lower my NOx numbers to pass inspection?
You did not mention the year and make so I will assume it is an older vehicle.





Retard the timing as far as the test tolerance will allow.





Cut the vacuum advance hose in the middle and rejoin it with something like a screw with the head cut off (this will block the vacuum but look stock to the naked eye.





Install one step hotter spark plugs.





Fill the tank with premium gas and add a bottle of octane boost to that from the local parts store.





Make sure the air filter is new.





If you have carburetor, adjust the idle screws about half a turn further out after the engine smooths (this half a turn further than a correct adjustment)





Set your idle to 950 rpm's.





run about a quarter tank of the gas through before you head in for the test and pour a can of ';guaranteed to pass smog'; additive into the fuel before you get the test done.





After you pass fix the vacuum hose with a hose union, advance the timing back to optimal, readjust your carbs idle screws and reset the idle to about 750 rpm's.





Good Luck!How do I lower my NOx numbers to pass inspection?
what vehicle do you have? catalytic converters been a brake-in period of 150 miles or so before they are efficient. also use the lowest grade fuel you can, it will burn more completely. you may have too much blow by from your rings. there are too many variables, we need more info.

soccer