What is wrong with it?

[thstone]

I'd be inclined to ask the mechanic check the idle control valve before replacing the MAF. Could be either component.

[Spinnaker]

This is just my own experience. Had the same hunting idle problem. Even after the complete 90K service at the independent, it still did it. Two years later the MAF kept giving me CEL's, so I replaced it. Now, no more hunting idle.
The easiest way to tell what MAF you have is to pull the old one and read the part # off of it like WhipE350 says.

[ProjectM96]

Thanks guys. I will try to find a torx set so I can get the old MAF sensor out to read the part number.