I just got done with a fresh engine rebuild on my N54. Bored .20 over, Pistons, rods, single turbo, sheet metal intake. It started up and runs great, but on decel i get a ratlle type noise, that best i can tell is coming from the VC or intake area, followed by an immediate check engine light. The only codes are 2aa5 for camshaft sensor, outlet, tooth failure, and 3100 due to the code. When i use ista and run the test plan, intake passes, exhaust does not. I double checked my timing, swapped vanos solenoids, swapped exhaust cam sensors, checked the non return valves in the head, swapped exhaust vanos unit. Any other ideas? This one is getting me stumped. It does have a new timing chain and guides installed. Any idea this is JB4 or MHD related?