I am following up to posting I had last week. My CEL is back on after replacing the O2 sensor twice in 3 months. I have 3 diagnostic codes which indicate a pre-cat sensor. Codes: PO130, PO131, and PO170. These indicate a bad O2 sensor that is causing a lean gas mixture. I took out the MAF and sprayed it with CRC MAF cleaner. My car is a 2003 SLK230 with 61Kmiles. The CEL did not go out after cleaning the MAF. I also notice an exhaust odor whenI pull into a parking place. Could anyone give me some advice as to what it could be? My car is not under warrenty and I dont want MB to overcharge me for exporatory repairs. thanks

jay

 

in your case you need ti look at cam advance unit wire for any oil in the system,trce oil to engine control connectors ,thats wats causing o2 sensor fault........let me no how u get on NAZ B