I have watched mostly all Nathan's and Doctor Dean videos and they have been very educational but I cannot figure this out. I have an 08 328xi with N51 engine. When I purchased the car it had misfires that would not go away due to burning oil from valve seals and noisy lifters and smoking. I solved these problems by replacing the cylinder head with a low mileage 2012 head. Car runs fine except for 2a99 code for exhaust camshaft correlation. I have tried all the things you guys mention...replaced solenoids, replaced cam sensors, checked bearing ledges(they are perfect). Then I opened it up again and replaced vanos actuators for intake and exhaust cam and retimed the engine with special tool all this to no avail. When I reset adaptations in INPA the code goes away and runs fine on idle then as soon as you accelerate the exhaust cam goes extremely retarded out of red range in INPA and code reappears. PIC ATTACHED.. Any info on what to try next would be appreciated.

Are you sure they were fine usually what happens the moment you remove them from another car they are nackered I wouldn’t trust used or Chinese parts just buy new ones and check trust me make sure you reset engine adaptions before installing that to me seems as tho they ain’t advancing the timing properly and stopping pulsing that’s what usually that code is for not camshaft sensor believe me
Yes rich n51 is basically n52 engine and if I’m not mistaken due to having a sulev engine the power band is brang down to help emmisions so in turn they fitted the 3 stage manifold to take up the slack and help power without giving out so much emissions your code is normal on most of these bmws they suffer with them the reason for your code your using cheap vanos solenoids ain’t you mate are you using genuine bmw ones if not that’s the problem behind it don’t use these cheap $50 dollar ones I keep telling people you cannot use these on this car lose them get genuine your problem will be solved trust me
i don't have an answer, just curious, an N51 is basically an N52 correct?