Weird O2 sensor readings

[al860]

Hi Everyone,

Just bought a 2002 C180 and had a few potential probs with it.

First off the auto transmission occasionally seems to stick in second then yesterday the EML came on.

Found out the EML light was due to an engine overspeed so read that with the OBD and reset with no reoccurrance so far. It did however indicate that the fuel system was in Closed loop but potentially only operating on 1 oxy sensor. I'll try to attach the print out but essentially sensor 1 is fluctuating between 0.1 and 0.9V but sensor 2 is around a constant 0.9V (read using ProScan).

A bit of reading suggests this is a rich setting but not normally a failed sensor.

Does anyone know if either of these sensors are bust, or if not how I can get the fuel system to stay in closed loop without any probs.

There are no oxy sensor or other DTC's registering.

Thanks in advance,

Alan

 

[al860]

Quick update incase anyone can shed some light on this.

Engine management light came on again but with a P0700 (transmission problem). The car generally goes well but sometimes the transmission sticks in second (i think). I'm thinking this could be due to a low transmission fluid (especially since I found a small leak at the back of the plastic cover, dark reddish?).

Anyone got any ideas, I will try to get it into a garage this week but any advice beforehand would be welcome.

Al