[sjed]

F11 523i with N53 engine.

Engine light turned on driving 110km/h on cruise control. Luckily I had Ista with me so on a parking of a gas station these codes were pulled.

The car is pretty much undrivable, running very rough. Back fires in the air filter housing, not keeping idle and shutting down.

I have switched coil packs and plugs with a known working cylinder. That did not move the misfire. Switched injectors, error is still at cylinder 5.

Injectors are 60k km old, replaced in 2019 by the previous owner for index 11. ISTA did indicate they were not correctly callibrated to the DME, so that is something I did and that error went away.

Next up is a compression test, but I understand headgasket failure is very uncommon in these engines.

Do you have suggestions for me? I am thinking maybe HPFP/LPFP, although last time I checked (couple days before the engine light) the pressures looked in spec.