On a 10 yr old car it's just a matter of time until the MAF fails, if it hasn't already. Tons of posts about this. My mechanic said mine's on the way out in my '02S w/74k miles.
I'd spring for a new one from a trusted source (not eBay). From what I've read ************************************************************ seems to have consistently competitive MAF prices. For your '00 they have two Bosch units available at "special sale prices": Non-e-gas type for $155.96 and E-gas type for $216.51. I believe '00 is the first year for e-gas.
Pelican Parts shows two part numbers for '00 (both e-gas): 996-606-124-00 for $233.50, and 996-606-125-01 for $286.00. I think the 125-01 is an updated version of the 124-00. Someone will I'm sure chime in on this, but there are other threads you can search for these details.
Regarding part numbers, you may find this useful:
http://www.renntech.org/forums/index.php?showtopic=2627?
Once you know exactly what part number you need, and I think it's the 125-01 based on the thread above, shop hard.