2013 X3 2.8 engine malfunction reduced power msg

[Skowrone]

Has 99,000 miles and occasionally getting flat power output followed by the drivetrain malfunction message “running with reduced power”. Plugs and coils were replaced recently. This is a similar symptom to engines afflicted with carbon buildup on the intake valves. The dealer never heard of cleaning the intake valves on this 4 cylinder engine and couldn’t quote a price since they didn’t have a procedure in the shop manual. Has anyone cleaned the intake valves on this engine?

[jclausen]

So start with faults first, then decide the next move, right now you have no idea what is causing the problem