Emissions failed in NJ need help please

[voltes v]

Hello,

Ok here's the deal. I took my 93 240 to inspection 2 days ago and it failed emissions. Here are the results:

NOx 592 PassHC 194 FailCO 1.70 FailCO2 13.3O2 .5

The car previously had a full tune up 3 months prior.

Afterwards I changed the sparkplugs to Bosch Platinum Plugs and get reinspected. I fail again and now the numbers are higher.

NOx 243 PassHC 215 FailCO 2.20 FailCO2 13.6O2 2.1

The guy said something about the levels were going up and down, sometimes low and then really high but car was idling normal at 900rpms.

I need advice on what I should do, NJ has this thing now that all repairs have to be done by specific facilities, but I don't want to pay through the roof for repairs. My other choice is to do the repairs myself but I have to supply all receipts for the parts replaced and used. The check engine line does not come on and car runs smoothly. The last thing I did was to clean out the throttle body/plate cuz the car kept dying after switching the clutch to neutral. I thought for sure the car would pass cuz the idle was good and no more black smoke during startup I think. I do have a feeling the car is running a little rich cuz gas goes down faster I think but I'm not positive. Any help will be appreciated.

Thanks

[gumby]

uh... i dont know if im the best person to answer this.

make sure the 2 tiny wires inside the mafs are intact. it will run rich if theyre broke. clogged O2 sensor will also. NOx passed so the egr is ok. you have an aiv system? remove it it can only cause problems.

how many miles and how much smoke? rings could be worn. heavier oil might not burn as fast.

hopefully someone else could chime in here