Hi i have a 1999 c class 220 cdi for 3 weeks now and i have a problem because didn pass the emissions test. The car release black smoke from exhaust. I checked for dtc and no code. The mechanics says maybe are the injectors runnin rich and the car do not have a proper air fuel mixture . Checked the egr , maf sensor changed the catalytic converters, oil and filters. The injectors are in correct values from the obd reading , 0.345 -0.203 something like this i cant remeber on idle. I see maybe a long time ago the first injector had a black death because is a old fuel deposition but now seems its not having black death issue and doenst seem to have any injector noise. Thanks for reading and hope to give me an answer.
Remove the intake tube near the turbo so you can look inside the vanes of the turbo for oil residue from a leaking turbo oil seals? Make sure the air filter is new also. If turbo has oil in it then engine is sucking oil into engine and will smoke excessive. You will need to replace or rebuild turbo to fix.
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