HC-values MB 320 -92
I have some problems with exhaust gases. The car is MB 320 10/92, 157000 km driven. Lambda-censor changed in 155000 km by car dealer.
The exhaus gas values are followings at 700 rpm:
CO: 0.5%
CO2: 14.4%
Lambda: 0.97-1.03
and HC: 160 ppm
What could cause the problem for the high HC values? The answer of local Mercedes Garage was that the only possibility is to change the whole catalysator and pipes and wasn't that helpful after all. When I asked from other people who have some experiences about the MB's the answer was that it could be probably because of active carbon filtering, but the local garage denied that one as well.
One solution would have been driving the engine hot, but it was already hot enough (20 km at 100-120 km/h)
So the only reasonable answer I've got so far is that it could be probably if the old owner has driven long time with the broken lambda censor that could cause some catalysator insufficiency and should be better by time. But I should pass the gas test in one month so I don't trust that it would be the only reason.
Would somebody have some ideas for the malfunction? Would it help if I adjust the injection? Or would the reason be in valves?
There hadn't been any other problems with the engine, as far as I know. The engine is running very smoothly and seems to be ok. I have owned the car only for one month and driven 2000 km with it, so I can't tell that well. It wasn't in use almost for three years.
If somebody could help me or have some good answers I'd very thankful.
Regards,
Markus
Subman
But it seems to be the only possibility.
If any other (cheaper) possibilities would be in question I'd rather do those.
Thanks anyway,
Markus



