1985 Mercedes Benz 300td

Engine Performance problem
1985 Mercedes Benz 300td Two Wheel Drive Automatic 150000 miles

exorst pipe bleck smog-only in low speed?
May 30, 2009.

Sounds like its running rich

Possible causes include a bad O2 sensor, excessive fuel pressure (bad fuel pressure regulator or plugged return line), leaky fuel injectors, dirty air filter or restricted air inlet, or a defective coolant sensor that prevents the engine management system from going into closed loop mode

May 30, 2009.