how do i lower my oxides of nitrogen (nox) in my car to pass inspection
You have to take it in for a “tune-up”. A car this age may need a number of things replaced, such as the EGR valve, PCV valve and other items. If you are a mechanic, I don’t need to tell you that, if you are not a mechanic, you will have to trust the person who does the work.
This is not something where you can just turn a few screws and be done. Budget $300+ or so to avoid any nasty surprises.
Doc is correct.
While the EGR valve is most directly related to nox emissions, replacing the air filter, spark plugs and PCV valve will also help the engine to run better/more efficiently.
A more efficient/better-running engine=lower emissions of all pollutants.
The bonus is a probable increase in fuel economy and power.
Make mine another vote in support of Doc’s suggestion.
Doc is right. A tune up, and filter changes, a test and replacement as needed of EGR and PVC valves and hoses, can do wonders for the nox problem.
sorry, typo, I meant Positive Crankcase Ventilation valve. PS I failed all my spelling tests up til the 7th grade.
Information given is general, what should be done is develope a through understanding of the system used on this paticular vehicle (we don’t even know the year) and then get very specific towards the system actualy used.