Hi All,

I just failed this years smog test because of NOx. The car has 180K, and runs well. The test is on a dyno. In preparation for the test I did the following:
plugs, fuel filter, new thermostat, cleaned the TB, ran some top end cleaner through to knock any carbon out, replaced any suspect vac. hoses, premium fuel in the tank and a fresh oil change 5 miles prior to test.

The test results as follows:

15 MPH 1738 RPM
%Co2: 14.5
%02: .3
HC: Meas 77 Max 114 Ave 31
CO%: Meas.48 Max .73 Ave .1
NOx: Meas 1007 Max 785 Ave 237

25 MPH 1755 RPM
%Co2: 14.5
%02: .3
HC: Meas 71 Max 88 Ave 20
CO%: Meas .51 Max .61 Ave .09
NOx: Meas 848 Max 724 Ave 199

I have read most of the FAQs and posts. Any thoughts out there. The car has the original O2 sensor and CAT. I would like to know if there is anything else I can do before I start throwing money at it. I don't think my multimeter is sensitive enought to check the O2 sensor.

Any help would be great!

Thanks,

Bill