The MAF (Mass Air Flow Sensor) sensor is a very important sensor that helps measure the amount of air coming into the engine. MAFs will get dirty over time even though they are behind the filter. I got the idea to clean the MAF sensor on my GST when I had to do it on my mom's Toyota Prius. The Prius would get angry and throw codes on the little touch screen and suddenly kill the ICE engine making it only run on electric. The cause of this problem was that the MAF sensor was dirty. So I cleaned it and it never stalled again.
So I thought well my GST has a MAF I should probably clean that as well. All my other cars have MAP sensors or AFMs. Cleaning your MAF will help your MAF get the most accurate reading possible at least where the MAF is concerned. I also cleaned the connector and pins on the MAF as well, this is a little maintenance I learned from owning a 76 280Z. The connectors were all old and starting to corrode, which was bad for connections and well that's how cars work nowadays electronics.
Here is what you will need (take not that I have a K&N FIPK intake installed so you may need different tools to get your MAF out):
A wrench or wrenches
A flat heat screw driver
A phillips head screwdriver
A Can of Mass Air Flow Sensor cleaner (You can find it as your local automotive supply store)
Here is a closeup of the MAF cleaner. I bought it at Winchester Auto for about 8 bux, its made by CRC. You want to make sure you get MAF cleaner (not engine degreaser, electronics cleaner, intake, throttle body, etc...) because it is designed to clean the MAF without harming the body or the sensor. Even sez it'll give you more horsepower!! Or more like restore it.
First you want to get the MAF sensor out. Not hard, just undo the clamps that hold your MAF in, just get it out by any means necessary without breaking it and disconnect the wire from it
Now that you have your MAF out it should look like this if you have a 2G
Now take that can of MAF cleaner, shake it up good, and spray away at the inside of the MAF. Make sure you get both sides. Spray it until you stop seeing dirt drip down from the excess.
Here's the other side without the honey combs. You want to make sure you get the little wire/resistor hanging on the top there in the center where its rectangular. That is the MOST important part of the MAF. When I shot it with the MAF cleaner it turned from black to a orangey color. So you'll definately know if your MAF was dirty if it does that.
Now as a bonus I cleaned the MAF connector. If you notice its dirty or the metal looks dirty and dull you might want to do this. I took a can of electronics cleaner (make sure it says plastic safe I'm pretty sure they all do though) and shot the connector on the harness and on the MAF. If the pins are really dirty you can get a scraper or pick and clean it up so the metal is showing nicely. This'll help make sure you get a good connection.
Then just put the MAF back in the same way it was before and connect it. That's it, very simply and maybe your car will be running better. You could also clean or replace your airfilter when you do this. You could clean the MAF if you just took your filter out but where would all the dirt go, down your intake pipe and into your turbo O_o'.