Urgently need help with ca smog and high Nox

[crzycrkr]

I have this posted in the 24tech forums, but moved it over here. Please Help!

I have an 89 240sx SOHC and am having a hard time passing smog again. Car has 241,xxx and runs great. my smog test showsRPM %CO2 %O2 HC(max/ave/meas) CO(max/ave/meas) NO(max/ave/meas)15mph 1726 14.7 0.4 118/31/38 0.75/0.10/0.03 799/237/47625mph 1733 14.6 0.3 93/20/20 0.63/0.09/0.09 738/199/1207Plugs have just been replaced and old ones were tan all around. new oil, fuel filter, timing is good, maf and air filter cleaned. The guy doing the smog check seems to think the car is running lean to cause the nox to be high, but everything else to be low. Checked the vacuum to the egr and the egr itself and both are fine. I am out of ideas as to what this could be and I really can't afford to pay someone to figure it out for me. Can someone tell me exactly how to check the o2 sensor and injectors with a meter? I am not to good with electric, so idiot terms would be greatly appreciated. Any other ideas what this could be? I am out of time on this, so help would be greatly appreciated.Thanks

[crzycrkr]

I am also kind of confused as to why I passed nox at 15 easily but at 25 my measure was too high even though the average was lower.

[Q45tech]

Nox is almost always egr related...........inside plenum port obstruction, dirty pipe or valve or control hoses, solenoids.

When you manually force egr to work does the idling engine die or run rough? If not an obstruction.

Use a few Techrons to clean injectors but I cannot imagine them clogged enogh to be so high Nox with the low other readings.

The Factory FSM has all the diagnostic proceedures

If you cannot afford $100 to diagnose should you be driving especially in CA?

[crzycrkr]

Manually forcing the egr does make the motor stumble. Tested vacuum to it and it was good. I've been runnign seafoam through the vacuum line into the manifold. It's kind of hard to afford anything if you can't drive to work.

Any other ideas?