Just replaced my MAF on the Boxster. The car was missing on acceleration and idling rough with RPM variable. I tried removing the MAF and cleaning with CRC MAFS cleaner. It said in the manual that it "may" help to do that. It did - about half way.
Checked with the local Porsche dealer. On sale the "Porsche" MAF was $565. They said to be careful about aftermarket parts.
I ordered the MAF from Pelican Parts. $235 and guess what the part that I bought was the same Bosch as the original down to the last number and symbols. Took the car for a run after install and it did very very well. Too bad about speed limits (not that we pay too much attention to them).
The Forum has helped me a lot over the last few years so here is my suggestions for an easier MAF change: 1. Buy the Torx 20 tool for the MAF removal. I found one for $8 for the complete set. You will only use it maybe twice so the expensive one is not necessary. 2. Buy a 1/4" socket knuckle to reach the outboard bolt with the Torx tool. Just makes it the easier. 3. This is important! Roll up a towel and place it under the MAF on both sides. That way when you drop the bolt it won't drop under the MAF GOD KNOWS WHERE and take you an extra hour the find the thing again
. Oh yeh - I forgot the trip to the auto parts for the angled mirror that I could not find in my shop.
Other than that it went really well. Needless to say if the MAF is bad you should replace the air filter at the same time.