Help!!! High NO level and wont pass emissions.

[Edsel58a]

Everthing else is low but the NO level is about 180 units above max. What should I look for?

 

[BrooklynBay]

How old is your catalytic converter? When was the last time you replaced your plugs, wires, filters, and other parts? Do you have any CEL coming on? Was your vehicle cold when they performed the emissions test?

 

[Edsel58a]

Converter, original, plugs, wires, filter: Not yet, just bought truck. Filter looked lightly dirty. Check engine comes on everyonce in awhile, but goes off by itself.
From my understanding it is an EGR issue....
Test location was 5 minutes away. Went there first thing in the morning.

 

[TheJMan]

EGR was not installed on Explorers until midway through the 1993 model year. High NOx usually results from combustion temperatures that are too high. This can be caused by many things, but the first thing I would do is at least run a quality fuel system cleaner (such as Techron) through the fuel tank to reduce any deposits that may be in the fuel injectors or the combustion chamber. A good Seafoam treatment may also help in removing carbon deposits if that is causing preignition.

Also, just make sure the normal maintenance is done. Plugs, wires, filters, and lubicants.

 

[BrooklynBay]

I saw some chemicals in AutoZone explaining that you will pass emissions, or they will give you your money back on the bottle. You could try it, and see if they really work. They are strong cleaning chemicals.