1980 450SL emission problems
 

I have a 450sl that can not pass the emission test in CA it's pass the HC and CO part of the test but failed the NO part it measure 2294 at 15mph and2137 and 25mph the max is 1277at 15mph and 1137 at 25mph does anyone have any suggestion on what i can do to lower my Nitric Oxide levels in this 450sl it was suggested the the EGR needs to be cleaned out or repalced but there isn't one on this 80 450sl and i can't find a vacuum dia. for it...

Look at the emission/tuneup label in the engine compartment. It will have a series of letter codes indicating the types of emission control devices. What are they? The label will also state if it is EPA (49-state) or CA certification. Which is it?

Also, what is the ignition timing specifaction on the label and what is the measured timing on your test report?

Duke