[onewhippedpuppy]

I think you can check resistance across certain terminals on the MAF, but I'm not sure.

Just look at simple cause and effect before you get too deep. You had the issue pre-timing belt change. You cleaned the MAF and it provided a temporary gain before defaulting back to the the prior issues. If your cam timing was off a MAF cleaning would not make the issue go away.

Do you notice any changes simply unplugging the MAF and driving? That's an easy way to determine if your MAF is totally shot, it might not be as effective if the issue is intermittent.