Got thru my summer projects - back to the Benz.

Pulled 3 codes:

Code 13 - intake air temp reading illogical
Code 22 - O2 sensor heater voltage illogical
Code 31 - Intermittent contact engine coolant temp sensor

Hard to believe all 3 of these devices went south at the same time.

Will check wiring on devices for codes 13 and 31 and clean int air temp sensor with some MAF cleaner as per a comment made by Arthur Dalton in a previous thread regarding that device.

The O2 sensor being shot is not at all hard to believe. As mentioned above, MBDoc stated in an old thread it's the most common cause of a CEL in my vehicle and likely others with an M103 engine.

Will update this thread when the CEL is cleared.