I tried CRC Mass Air Sensor cleaner on my AMM this week. Amazing results on my 240 with 241k! Removed the meter and blasted several times, using ~3/4 of can up. Prior to cleaning, my wires had no "noticable" crud on them, but they were black in color. After a few spray/dry cycles with the CRC, the wires and the venturi turned super shiny, with no other work. Put the AMM back in and did a 100 mile trip next day. Did a long, straight 3 mile hill with 10% grade that I travel often. This hill had always required a drop to 4th gear and full throttle just to keep at the 55mph speed limit. I was blown away when the 240 took this hill and maintained 60mph with relative ease in 5th gear! I was actually able to accelerate and pass someone in the process! (it's 4 lane road) No Bull. Of all the tune-up things that I've tried short of a rebuild to get this car to move a little better, this has been the best investment yet. Can't wait to check mpg.

Notes:
1. Remove the AMM from the car to do the best cleaning.
2. When spraying, use the extension nozzle, and press the button full down to get max pressure blast. Don't be shy. This stuff dries quick.
3. Never touch the wire with anything. The spray is all that's needed.
4. Up until ~6 mos ago, I had been using a K&N air filter for 3 years prior. I have heard, and now strongly believe that the oil required on these filters eventually gets coated on the AMM wire. I know, people will say I probably put too much oil on it, but I don't think so, and I won't be using this type of filter again. There's too much voo-doo involved in maintaining these filters.
5. I checked my burn-off function with multi-meter, and it was working. Thus, I'm assuming the burn-off doesn't clean everything, especially film build-up and oxidation over a long time.
6. The CRC was ~$7 at Advance Auto or any major chain. CRC recommends cleaning at every air filter change. Will do.