F30 320d Drivetrain Error

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Hi Guys,
I'm having a bit of drama getting a resolution to an error code on my 2016 320d. I took it to one local garage, they said it was a flexray issue, a second garage refered me to a third as they don't deal with flexray, and the third said it wasn't flexray at all!

After the diagnostics were run, its coming back with:
28DE00 - Exhaust back pressure before turbo
28EC00 - Exhaust gas pressure sensor upstream of Exhaust turbocharger
290900 - Air mass system, measured air mass too high
290B00 - Air mass system, measured Air mass too low
2AB600 - Exhaust backpressure sensor before turbine too high
36F500 - Air intake system: plausibility

I'm not expecting free mechanics advice, but just to check my logic. It seems like a straight forward Exhaust pressure sensor swap would sort this, as the equal/ opposite nature of the faults leads me to believe the car doesn't know what's going on.

Anyone of you lovely people had any similar experiences with this?

Cheers

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It's driving normally to be honest. It states high performance not available, but I can't tell

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EGR replacement through the recall about 8 weeks ago. If that's what's gone they'll replace it. It's going into a local garage next week. I was intending to replace a few easy sensors myself to see if that sorted it, but its MOT is due soon, and I've not got the time to have a few stabs in the dark. It'll be interesting to see what needs doing.