'80 280SL & CA Smog Test
 

Spent the morning doing a pre-test to determine a baseline. The car is an '80 280SL with a 110 motor. Following are the results:

15 MPH

HC=138-Pass
CO=.61-Pass
NOx=1861-Fail

25 MPH

HC=124-Pass
CO=.58-Pass
NOx=1651-Fail

This car has NO emissions equipment, including a lack of cats. Timing is set at 10 degrees BTDC. 80 degree thermostat and new plugs. I'm considering installing cats tomorrow. Are we on the right track? Any other suggestions? Thanks in advance!