So what is the MAF thing anyway and why do I care?
The MAF is the Mass Air Flow sensor. It's the thing that is between your
air filter box and the large rubber hose that brings the air into the top
of the engine. There's a little sensor in there that measures how much
air is coming into the engine, which in turn the main computer figures out
how much gas to inject into the cylinders, giving you a smooth ride. If
that MAF sensor gets dirty, it gives incorrect readings to the main
computer, so your engine runs rough. The MAF sensor should be cleaned
every so often but you have to be careful with it as it's easy to break.