I just cleaned the MAF in my 1994 toyota pickup.I did not touch the sensor inside the MAF.After letting the MAF dry for 10 minutes, I re-installed it.Then I crank it up.At first there was a low pitched (audible, but not loud) DU DU DU DU DU DU DU (liked a muffled high performance exhaust) at idle.When I first staring driving (after I cleaned the MAF) it was kinda loud.I took it for about a 10 mile drive, and the noise got quieter.But I did not notice any change (for good, or bad) in the engine performance.Drove just as pretty as you please.Idled good to.Once I got it home, and let it idle, I could still hear the DU DU DU DU DU noise but not as pronounced.I did a code check and it came up clean.

Does anybody have any input?

Sounds good, keep cleaning stuff, Air filters , Emissions...all that...and it will keep on rollin rollin rollin...

where is the noise coming from. maybe you didnt close up the intake tubes tight enough and air is getting sucked through the cracks

Sounds like there may be an air leak. Check for a misalignment in the tubing and hoses that you disconnected. If it ran fine, chances are it's somewhere on the intake side of the MAF.