I have an ’03 X-5, 3.0l e53 with 225,000 miles. I’ve been using after market inexpensive MAF sensors .

When the MAF sensor fails the car will go into Emer Trans Failsafe mode immediately on start -up. Put in a new one, wipe codes and the car will drive perfectly for about 20 miles then trigger the trans mode, not full limp home mode, just a slightly reduced transmission performance.

It’s throwing a lot of codes but I can’t see which is triggering the trans mode. Since performance before the mode is triggered is perfect I’m assuming there is a bad sensor elsewhere, perhaps temp related that’s causing this. Any one seen anything like this? Suggestions on what could be causing it?

If I shell out for an OEM sensor would it help?