Emission test help. I got a 93 Topaz that had high Nox. What should I do?

Answer 1

It really depends on where you are. Here in Massachusetts they don't have to tell you what's wrong, just that there is a problem. The answer here is to go to a certified emissions shop where they will try to fix the problem, whatever it is. Here, if you spend a minimum of $200 at a certified shop and the problem hasn't been fixed they are required to give you a passed sticker.

You may want to research what the state regulations are in your part of the world, but I would guess there is a similar ruling. Don't go by what they may tell you at the service station. I asked them first myself, and they told me it was $1,000! You're much better off reading the law on line.

Good luck!

Answer 2

I agree with bartzan41. Have your mechanic check the operation of the EGR system for clogged EGR passages, a failed PFE sensor, a stuck closed EGR valve. Also verify the engine isn't overheating. An engine that runs excessively lean, or is overheating will definitely show high NOx readings. Hope this helps.

Answer 3

Make sure the egr ( exhaust gas recirculation ) system is functional. The egr valve's sole purpose on a car is to reduce nox ( oxides of nitrogen ), by adding inert gases to the combustion chamber to reduce the cylinder burn temperature. The inert gases are simply exhaust. Also, if the engine is running too lean/rich, it will affect the egr system performance.
Some things to check anyway, hope this helps ....

Answer 4

if sensors have the splendid readings then they're ok,i might ought to assert its the converter very uncomplicated on the older automobiles they get burned out and don't warmth up like there meant to with a view to burn unburnt gases in exhaust.maximum converters arise to 1400 deg. vehicle tech.27yrs.

Answer 5

The shop that tested it didn't tell you what repairs need to be made? Ask them, then have them make the repairs.