Un-erased fault codes
 

I am just curious to know if un-erased fault codes will keep an engine's computer running in fixed operating mode even though a repair was made? (O2 sensor, bad EHA, etc)

TIA!

~Paul

__________________
'91 300E, 215K miles

I don't know specifically about Mercedes, but I really doubt it. The computer stores the codes simply for retrieval purposes. This allows the mechanic to diagnose the problem, and even helps with intermittent faults. There's no feedback mechanism to control the engine's operating parameters.