After many months of reading and learning of trouble areas and repairs on the DMC, it is now my turn so here goes. I just took the "D" for its emission test here in Arizona and failed the portion that deals with oxides of nitrogen (NOX). The brochure provided to me by the testing described what to look for: 1) Possible EGR system malfunction 2) Abnormal engine operating temperature (car has run consistently within normal temperature ranges) 3) Air management system 4) Lean air/fuel mixture 5) Catalytic converter efficiency 6) Over-advanced off-idle timing The question I have is out of these possible causes, which is the most likely to cause this failure and have checked first, then second, etc.? I'm sure this has occured to someone else and any assistance is greatly appreciated. FYI, the car is a 1983 automatic with 2,760 miles. Thanks again. Mark D. 16728 Plate -- OUTATME ------------------------------------------------------------------------ To address comments privately to the moderating team, please address moderator@xxxx