High NoX emission

[gbright]

My 1989 300SE has been doing swell at 124,000 miles...still uses almost a quart of oil in 3,000 miles!

In Atlanta we must have emissions tested every year. I noticed last year, the Benz passed by ONE point on the NOx scale.

In the past on another car, someone told me that when the NOx is high, the EGR is bad/failing.

I put a can of 44K (made by BG Products) in 10 gallons of premium gas as recommended by a friend--I have no connection to the company. He said this would help to clean out the carbon in the head, along with a 100 mile run on the interstate.

Question: If after this "treatment," the Benz fails on NOx, what do I try?

Thanks for your help while keeping this "good one" running for a long time.