How to Clean the MAF on a 2003 Audi TT Automatic Trans

1. Open the hood. Disconnect the secondary air-injection hose that plugs into the lower part of the air-box by pulling it off.
2. Remove the two Phillips screws at the rear of the air-box lid. Release the plastic tabs that also hold the air-box lid in place and remove it.
3. Disconnect the wiring harness that plugs into the MAF by pressing on the plastic tab on the plug and pulling it off.
4. Remove the two screws that hold the MAF to the air-box with a Phillips screwdriver. Set the screws aside.
5. Loosen the self-squeeze clamp that holds the turbo inlet pipe to the MAF with a pair of joint pliers. If the clamp has been replaced with conventional hose clamp, loosen it with a Phillips screwdriver. Push the pipe gently out of the way.
6. Pull the MAF gently out of the air-box. This may take a little maneuvering to do safely.
7. Spray MAF cleaner -- available at an auto parts store -- on the glass screen, sensor and plug area of the MAF. Most of the cleaner will evaporate. Wipe any excess cleaner off with a lint-free rag.
8. Reinstall the MAF in the air-box. Plug in the turbo inlet pipe. Connect the wiring harness. Reinstall the secondary air-injection hose. Reinstall the screws that hold the air-box lid in place and ensure that plastic tabs are holding it securely in place.