We drove to the in-laws ranch, 50 miles each way, for family Christmas (hers...mine are all gone). I'd never driven the X5 on hills, switchbacks, gravel, etc., nor at 75+ mph for long stints (previously only getting on the freeway on short trips).
Overall, it was surprisingly agile and definitely handled railroad crossings, potholes, and the gravel-covered approach to the ranch (a long downhill curve on a tall hill; coming back up it is easier with the X5's AWD) better than any of my 2WD trucks or FWD compact daily drivers do. It does downshift faster and more often than my V-8 trucks do on high speed hills (of course there's less torque and horsepower available than the tuned 5.7L and 6.0L trucks possess), but it was finely controlled, and the speed increase was just enough. I still haven't mastered the Cruise Control though; one click up gets me much more increase in speed than the CC on the GM trucks.
Also, on this trip, I intentionally watched for the kick-in of the opened DISA valve at about 4000 rpm; it really makes a difference (before the DISA upgrade/repair, there was no difference on two "floored" attempts).
Now for the Service Engine Soon codes (there were also about 8 more hidden codes concerning steering angle and other momentary, "implausible" codes, that go away by themselves). Again, there's the P0365 (exhaust camshaft sensor), but this time accompanied by a P0505 (idle air control valve not working correctly). The P0365 triggered at a completely different situation than it had previously:
so I assume that I need a new camshaft sensor, since it's showing signs of variance in different situations. The P0505 is new, though.
I saved the P0505 freeze frame, but when I brought the Foxwell scan tool into the house to photograph it, it wouldn't display it.
I guess I should've removed & rattled it when I redid the DISA; is it necessary to remove the DISA to test the idle control valve?
It may just be pointing to an intake vacuum leak; I still haven't smoke or visually tested there, nor have cleaned the MAF, either. Though the P0171 and P0174 codes haven't reappeared, I suspect they're not gone for long.