The N62 engine is prone to vacuum leaks and is also very sensitive to them when they occur.

I would start by checking for vacuum leaks using a smoke machine. I made one from a paint can and glow plug with a wick into mineral oil. Then I used a fitting in the lid for air pressure (3psi) in and a second fitting for air pressure/smoke out. Hook the air/smoke line out to the air intake past the MAF with a larg PVC cap that fits snug (I wrapped duct tape around the cap to gain the diameter I needed and threaded a fitting into the cap for the airline). Check YouTube for ideas on building your own smoke machine.

One other thing to check would be the injector for the cylinder. Swap it with a known good one and see if the misfire follows the potentially bad injector.

Lastly, if you haven’t found the problem, you may want to do a leak down test of that cylinder to check it’s overall health.

I had an E53 with an N62 that needed an engine replacement at 52kkm and had misfire which was undiagnosable at 160kkm.....I sold the lemon to a wholesaler.