Are you still running the oil gas? If so, drain that out and put clean gas in the tank.
I saw a website once that showed how to test the afm with a 9 volt battery. I don't know if it's bad form to post a link to other forums.
Here's another interesting video of extending the life of the afm. However, you can get good used ones for about $100.
YouTube - Rejuvenating a Bosch Motronic Air Flow Meter