2013 BMW X6 (E71) Misfire problems

[bobsnotnose300]

Hi Everyone,
So i've been lurking in various forum subs/threads for a while now trying to figure out the issue I have with this car. Its a 2013 BMW X6 with the N55 engine and has about 145000 miles. I bought it about 2 months ago, the spark plugs and ignition coils have been changed for all cylinders (according to the previous owner). After this he says the car started misfiring, it sat for probably 2-3 months while he tried to get it fixed and a BMW shop he took it to couldnt figure it out (said maybe it was the injectors). Anyways, I bought it for pretty cheap hoping I could fix it up. These are the codes I have, and this is the data i was able to get from the scanner I have (see attached). I previously had code 2A34, "Injector, cylinder 5, activation: Short circuit, high-pressure side, to low-pressure side." After taking it to my mechanic, he said the injector for cylinder 2 was going bad, so he replaced that with a brand new one. The car now runs a lot better but still runs pretty rough (especially on cold starts). Now, he told me if he were me he'd sell it because hes saying that as a result of oil burning, the O2 sensors are getting a certain signal which its then forwarding to the engine to turn off certain cylinders to prevent damage to the catalytic converter. Hes saying its already clogged though and the only way to fix the car is fix the oil burning problem replace cat, etc. which is obviously pretty expensive. From my experience driving the car thus far, I don't get why his theory would make sense but maybe im not aware of how fine tuned these cars are. I test drove it on the high way and cleared the codes mid drive just to see how well it would run (since the injectors per his theory would be active) and it immediately went back into limp mode, which makes me suspect the fuel injectors may be bad because of how quickly it happened. I dont really know where to go from here, and I just want some guidance if possible. He said the catalytic converter is already clogged so one loop around would be to code the O2 sensors themselves into "limp mode" so that they dont tell the injectors to turn off but I can't tell if what hes saying is whats actually happening. I also noticed that the right exhaust (passenger side) tailpipe is pretty much cold, but according to some threads I've read that's normal as its only active at high RPM ranges. There is a slight "rotten egg" smell common with cats that are clogged/going bad from the driver side exhaust. Also, just for reference, my MAF sensor is currently unplugged because the mechanic mentioned it was faulty and causing the car to run more rough. I was thinking maybe replacing the fuel injectors on 5 and 6 would fix all my problems given the data from the O2 sensors but I also don't know for sure what im reading (not much experience) Anybody have any comments/advice/experience with this? Thank you so much for the help!

[Freude_am_fahren]

This is the first time I heard of cylinder deactivation because of burned oil. I don't know if that really exists. I do know that they can deactivate cylinders when they detect a misfire. They cut fuel injection to reduce unburned fuel reaching the cat. You could do a compression and leak down test to possibly disagnose physical engine damage that could cause oil burning.

The first step should be in my opinion to get a new (or used one confirmed working) MAF sensor. Without it the car won't run right and any disgnosis might be falsified.