Need Help, Limp Mode, Exhaust campshaft sensor, gap loss code

[cybergio]

Hello all,

First, a little background on my car, BMW E60 535i manual, purchased the car few months ago, it was smoking really bad and also had misfires. I did replace both turbos, all six injectors (Installed brand new index 12s), spark plugs, oil pan gasket, valve cover gasket, oil filter and cooler gaskets, manifold gaskets, oil line gaskets and etc, basically did the full maintenance cycle.

After putting all together engine started with no issues, no smoke, no misfire, nothing, it worked like a clockwork, until the engine reached 5200 rpms, that's when I'm getting "Exhaust camshaft sensor, gap loss" error code and car goes to a limp mode. After I stop the engine and restart it the limp mode and a check engine light goes away, car drives perfectly, turbos are good and all until I reach 5200 rpms again and the same thing happens.

So I went and replaced both Vanos solenoids, both camshaft position sensors, all vacuum lines, both boost solenoids but with no effect. Inspected the chargpipe, bov and all the inlets, no cracks or anything.

Now I'm thinking it might be the chain tensioner or the chain itself, I am really confused at this point.

Did anybody had the same experience?