Trying to diagnose the (e70) X5m. I'm getting some sort of flutter and low boost codes and now misfires. Anyone heard this before...is it the wastegate not holding pressure? Or a vac leak somewhere?

https://photos.app.*******/ewzABbf8HtjbPaV3A
https://photos.app.*******/W9Sv314afTSogTiR6


Any ideas?

Bms stg1 / fabspeed exhaust mods

Now any WOT driving or harder acceleration cripples the car into limp (low power mode).

I'm sure I crapped out the plugs or coil..but that flutter is odd to me.

****Update****

So I went ahead and removed the stage 1 tune in hopes the aggressive boost map was causing the issues.

Able to run the car just fine but it does seem sluggish on speed but still quite responsive throttle wise. I feel there's some boost leak causing this.

I removed the stock air box and put 2 cone filters in place to hear more accurately. The result:

1) The flutter on throttle (building boost) still happens
2) Car seems to still recirculate air when quick releasing accelerator
3) No more low boost CELs triggering

So my thoughts are boost must be holding to an extent... but escaping fractionally on boost build somewhere.

My stg 1 probably damaged something old with the tune and now it's still broken even though normal boost has resumed.

Anyone have an easy vacuum diagram or must check points in the engine?

Thanks!