What is the proper way to clean it? If I touch the little prong will it damage the sensor?

 

I use CRC MAF Sensor cleaner. It's an aerosol...should be easy to find at most any auto parts store.

I can't visualize the "prong" you've mentioned. Best bet is to avoid touching anyhting....just douse it with few good shots spray.

Cheers
DD

 

By "prong" I mean the actual sensor bit hanging down that looks quite delicate.

 

If you refer to the "hot-wire" sensor*, they aren't all that fragile really. I used to clean the english Lucas one on my XJ6 with some electronic cleaning solvent sprayed on and a very soft small brush as used for water color painting. Then a blast of air from a bike-pump. One reason for a hot-wire getting dirty is a missing air cleaner element, or a modified one that doesn't get all the microfine dust particles out.
* These sensors work by the cooling effect of the air rushing past the filament. A current is passed through the filament to heat up the wire. Air rushing past cools it down, pro-rata. The electrical resistance of the wire changes markedly according to it's temperature, and this analog change of current can be easily turned into an analog change of voltage, which is in turn changed to a digital number, probably of the 8bit (byte) kind in the micro. (255 steps of control of course). The micro then controls the amount of fuel injected by controlling the "on" time of the injector, or pulse width. The hot-wire system uses no moving parts, rather better than the old-fashioned 'paddle in the air stream' and potentiometer previously used. Was that the "K-Jetronic"?
BTW, your tungsten lamp at home has exactly the same characteristics. Measure the cold resistance with an ohm-meter of a 100watt lamp, then use Ohm's law to work out the wattage and you'll get something like a kilowatt!
Leedsman.