2012 Xdrive50i - Weird behavior after oil change

[jimoreno]

So, I replaced the N63 engine in my X5 and finished around January. I installed a lower temp water thermostat before installing it and ordered the lower temp oil cooler valve about 3 weeks ago. It finally arrived this past Saturday so yesterday decided to change the oil, replace the oil cooler thermostat valve, add Ceratec and install the NGK 97506 plugs as I got a Dinan Stage 2 tune 2 weeks ago.
Did the plugs first, drained the oil, removed the valve and installed the new one and replaced a crankshaft position sensor that was one of the few parts that I didn't replace when I changed the engine.
Added the oil and Ceratec. Started the engine, everything was OK but when I drove the car later running an errand, I got the engine malfunction: reduced output message" and the car started stumbling. Using Protool I scanned the car and got code "2A87 Exhaust VANOS, mechanism". Tried to erase but it comes back immediately. Keep in mind that this is an engine with 3K miles, brand new (re-manufactured) from BMW so it included new VANOS, new camshaft position sensors, spark plugs, vacuum pump and oil level sensor.
Got the car back into the garage, waited about 2 hours for it to cool down and re-installed the old original from BMW crankshaft position sensor. No change, erase the code and it comes back. Waited another bit for the engine to cool some more, removed the stiffener plate and oil filter, re-installed the original oil cooler thermostat valve and same story, erased the code and came back immediately.
What surprises me is that it doesn't state which bank the error happening, both Protool and the Foxwell scanners give the same code. You can hear the engine is running differently (kind of louder) and obviously missing power.
Has anyone had something similar happened? A possible solution? I might order a single VANOS unit and try replacing one side first and see what happens. It makes no sense to me since I didn't tough anything besides the spark plugs, CPS, oil filter and valve