two codes, two questions

[Henn28]

I'm oddly happy to be dealing with two garden variety codes on my X5, and to be (hopefully) done with the big drama for a while.

My Foxwell for some reason doesn't poop out BMW or P codes, or I don't know how to convince it to. Therefore I dig into my Bentley book and match the foxwell verbiage to the BMW and P codes in the book.

1) Airbag light with a Foxwell code "6 MRS Side Airbag Front Right". Likely a G14 or G15 code. The code wouldn't reset with the foxwell (i.e. it failed to reset) so either I need to pull the battery neg. to get it to reset, or it is designed not to reset given it is a safety feature? My questions here are, are there any troubleshooting hoops to jump through before pulling the door panel and replacing the airbag module, how does one troubleshoot the actual airbag unit, and assuming that it is bad, should I buy a new bag ($300) or are Ebay pieces reliable for airbags in folks experience.

2) Foxwell code 7C, which I think translates to a P0112/0113 or a BMW 124 code: Intake air temperature sensor... I can't find a specific sensor in the intake track, nor do I remember one anywhere in the car when I had it in pieces, so I assume this is part of the mass airflow sensor and a MAS replacement will be required if it comes back (reset OK). The MAS is 20 years old, so it may be time! I've read that an OEM part (Bosch, I think) is best for this piece?

The car is running fine, so maybe it was just a spurious code and won't come back.