Come on... lets fix that car, selling it is a cop out.

While I would never advise using a Ford sensor in a MB, I do not believe it is your problem (directly). It will not be the problem unless it is either defective or possibly you have come across a different Ford application. The type of O2 sensor MB uses is very standard, the only for sure different types I know of are in Jeeps and BMWs (the 5v reference type). The japanese use some other types including a conceptual change on new Toyotas - no feed back cycle.

The reasons I wouldn't use anything except the specified sensor have to do with life expectancy and speed of performance. The sensors don't work until very hot and the design of the sensor airflow facilitates its use in specific exhaust locations. This performance deficiency possibility IS NOT your problem. YOU HAVE A GROSS ERROR.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician