We bought an 08 r56s with a blown motor. Installed a low mileage motor that was sitting around for a few years with 30k on it.

We got it running after replacing the DME and CAS module as the old DME was not communicating.

Now fast forward after replacing a few dead sensors like the fuel rail pressure sensor, it's throwing these codes and running a little rough on idle, and revving it up quickly it misfires. Revving it slowly it runs smoothly.
VANOS is stuck at 36* not moving.

2B51 Air mass sensor, signal -Did try replacing the mass air sensor
2883 Wastegate valve, Activation
28B1 Bypass Blow-Off Valve, Activation
287A VANOS solenoid Valve, Inlet, Activation -Did replace the VANOS solenoid with another genuine known good part
27B4 Tank-Venting Valve, activation
2B5F Air mass sensor Correction Signal

I have swapped around the wires for the tank valve and the other small module under the intake, as well have tried swapping around vacuum lines but no luck.

I am lost, any help is appreciated.

 

I too had the same assortment of codes:
List of codes only. They occurred in pairs, indicated by numbers/letters within parentheses.
2B5(F,1)
288(2,3)
28B(0,1)
287(A,B)
27B(2,4)
When codes were erased with scan tool, they would return immediately/instantaneously(!), suggesting an electronic failure, in my opinion, rather than a slowly evolving fault signaled during feedback loops while driving.
I noticed the insulation for two wires attached to the Air Mass sensor was split, exposing the bare wire that I covered with shrink wrap (see image).
The shrink wrap at mid-wire was where I cut the wire so I could install the wrap to cover the exposed wire at the base of the connector (circled).
You can see the impression of the split insulation under the shrink rap captured within the circle. The mid-cut wire was soldered and covered with wrap.



Next, I checked all of the ECM fuses in the fuse block under the hood on left hand (driver's) side (USA).
Fuse (F04, 20A, circled) was blown.


Considering the years of heat/cool cycles experienced by the engine and how the wire insulation suffers from these heating gradients, my next task is to check the integrity of the wire bundle underneath the wire loom.



The wires under the loom were stressed when installing thermostat, oil pressure sender gauge, vacuum pump seal, or similar and worth it for me to check. I am expecting another short circuit to happen again.

 

BEAUTIFUL MAN! Thank you so much!!!

I owe you lunch and a beer.

Replaced the wiring harness after finding a short, and that fuse, and voila! BOOST!

Still getting cylinder 1 and 3 misfires, even with swapping coils, along with super knocking codes. Oh well. I'll check everything over tomorrow.

 

I forgot to look simple first and then started banging my head trying to figure out what was going on.. and then I happened across this post.… Thank you very much! 😁