[KillerM3]

Afternoon all, new here to the group. Had my M5 since last April 2021

It has always had a problem where it stalls when setting off and accompanied by an error on bank 1 and 2 that says air to fuel mixture too lean.

So far it has had brand new injectors, a fuel pump, new O2 sensors new MAF new spark plugs 1 new coil pack replacement ECUs with a fresh flash to factory incase it was ever previously mapped. I even removed the cats as one of the mechanics suggested they may be degraded.

Car has full service history

I am currently at a total loss as to what to do with it.

Anyone ever experienced anything like this? Or possible solutions. I'm fairly certain everything that could cause the fuel mixture error has been replaced.

Currently feel like driving it into a wall. It drives absolutely faultlessly apart from the stalling when you are setting off.

It doesn't do it when cold when the revs are higher only when warm and only when setting off. Apart from that no misfires, errors or anything else.

The oil smells strongly of petrol which I put down to the injectors but they were all replaced.

Any pointers would be much appreciated.