Can I clean the MAF on a 5.0 without removing it?

[rs2k]

I ask because there's what appears to be black epoxy on one of the torx heads. I tried to remove it but it's stuck in there good.

I'm pretty sure I have a vacuum leak somewhere in the system but I thought I'd try cleaning the MAF sensor first. I'm getting bank 2 lean on the O2 sensor. When there's a high vacuum (like decelerating) the computer is giving about 23% bank 1 and 28% bank 2 more fuel than normal assuming my scanner is correct. Cruising I'm showing it's giving about -1% on bank 1 and 3% more fuel on bank 2.

 

[SoNic67]

I did clean it by removing the air tubes attached to it and blowing cleaner to it. Didn't remove it from the plastic housing.

When MAF gets dirty, it shows PCM that you have less air. Therefore you will have less gas dumped into injectors, a lean condition.
O2 sensors will notice the lean condition and PCM will compensate, adding long-term corrections.

 

[rs2k]

After cleaning the MAF the long term adjustments went back up to around 25%. I'm guessing I still have a leak somewhere, but I can't find it. All the hoses I can see see fine. Maybe the intake manifold is to blame.