I had the same exact code in my 2000. It had nothing to do with the MAF position, vented oil fill, or oil type.

I had been running a superchip for months with no problems. I decided I would try a switch to a Diablo 3-way and this is when the code started to occur. Switched back to the superchip and have never had a problem since.

I would get with whomever sold you your chip and see whats up.