[havar]

I have a 525i 3.0L N53.

I had some headaches for the misfires so spark plugs, ignition coils and valve cover gasket have eventually been replaced.

However two codes still show up together: one is for the map thermostat activation (2EF7) and the other one is for NOx heating.

Before starting replacing this and that, I am thinking about checking thermostat first as I read that if it fails to close, the car runs cold, therefore more fuel thrown in and nox triggered. I didn't check the temp gauge. If that is ok, I would have to go and check the nox then.

Car has undergone a thorough refurbishment in the last few months and drives very smooth apart from an intermittent EML light which warns about a lean condition on bank 2 (which might be nox-related to probably due to the car running in homogeneous mode?)

Any suggestion would