From what I've read it is certainly possible for a dirty MAF to cause this condition, but if that car has 100k mi and hasn't had the intake boot replaced, it is likely the culprit. IMHO....
I've got two cars with the 3.0, both threw those codes at one point, and both needed intake boots.
There's a small offshoot of the boot that splits off for the idle air valve, I believe. That's where my cracks were on the X3, not on the larger bellows. As hard as I tried, I could not see cracks before removing it from the car, so the boot looked good and I was not super-confidant the boot was indeed the issue. But it was. The boot is very thin and the rubber is subject to degradation, so it gets brittle over time and it cracks between the bellows.
On the x3, I had to clear the codes, they did not reset themselves after having fixed the boot, even after driving several hundred miles. So, don't expect the codes to go away on their own...
Last edited by wamcneil; 04-16-2012 at 07:11 AM.