850i with blinking red CHECK ENGINE

[borcherta]

Hello forum,

we have an 850i with the M70 engine.

It started to behave a bit strange, so as a test we disconnected the 2 O2 sensors. Performance and overall handling was noticeable better and we drove maybe 2 or 3 days with the O2 sensors being disconnected.

Then the 850 was not driven at all for 2 weeks.

Now after the 2 weeks: engine cranks, it sort-of starts, idle is very very low, sounds not good and the throttle does not repond at all.


We reconnected the O2 sensors, disconnected the batteries (hoping to reset the ECUs) and charged both batteries over the night. Same behavior the next day unfortunality.

Seems to be the engine could be in some kind a emergency mode ...

Any thoughts?
thanks