It finally happened - my 85 190E 2.3 failed the emissions test - the readings were:

HC: 142.9 ppm (limit 189 - pass)
CO: 4.48% (limit 1.21% - FAIL)
CO2: 12.32%

I did all the usual stuff - take it for a spin on the freeway for 15 minutes, oil change, etc. before the test. Also, had a full tune up 10K miles ago (plugs, wires, rotor/cap, injectors, air/fuel filters, OVP relay replaced) - my car has 121K now.

What could be the reason? What should I look for? It also has a cold running problem - runs rough until the engine warms up.

I looked through the archives, but could find an answer to my specific problem.

thanks for your help,
Rags