P0393 engine code help

[nra0707]

I could use some help with an engine code that I've been trying to diagnose. I'll give as many details as possible. A few weeks ago, I gave my 2004 4.4i (N62) engine an oil change with Castrol Syntec 5w-30. A few days later, my X begins sputtering and lurching and the engine cuts out with a Engine Failsafe program message. I limped home and checked the engine codes. I got 2: P0390 and P0024. It seemed to indicate the Exhaust side Bank 2 cam position sensor. Thinking I ordered an OEM part from PelicanParts, I received Febi Bilstein aftermarket ones that I know people have had problems with in the past. Given that I need to get on the road for the holidays, I installed it anyway and it ran fine again. No stuttering and no engine shutdowns. The next day, I start the car and get an SES light. This time i got a P0393 code "Camshaft Position Sensor B Circuit High Bank 2. I figured it was the Febi Bilstein giving problems and went to the nearest Dealer to buy Factory. I replaced the part and it still gives me the P0393 error. It runs ok, but not great, and definitely not as bad as when I had the originally installed Cam Sensor in there. I think the fuel MPGs are still lower than normal.

So now I suspect that it may actually have to do with the Vanos Solenoids on the drivers side after reading something from Bentley Publishers online about N62 engines with that code. They are either gunked up, or I might have replenished the engine with .5 to 1 liter extra oil and it is affecting the vanos on the drivers side cylinder head. The oil dipstick is really difficult to read since it drags oil up the curved tube and messes up the level reading. In any case, I looked at the amount of oil i removed compared to what I put in and I've since removed the extra oil, but no change in code even after erasing them. I figure it might be worth taking the vanos solenoids out and spraying down with brake or MAF cleaner, but they are under a lot of venting hoses and also next to the radiator hose. It would take time, and it's a tight squeeze to get them out. Before I do that, anyone have any other ideas?

Thanks everyone