We also had a MAF Sensor code on ours. The mechanic tried to clean the MAF sensor with "Sensor Clean" spray and told us that the code went away.
We drove away and within minutes the Check-Engine light came back on.
I purchased the same product and cleaned it again thoroughly myself. No go. The Check Engine light came back on.
Not thinking that the mechanic would not have checked the air filter as it would've been the most obvious thing to do, I used a bit of...er... logic
...ie..."Air-flow" and decided to take apart the air filter housing and air filter.
Big mouse nest in the plastic pipe just before the air filter. Cleaned it all out. Fashioned a metal grill to place in the crimped part of the plastic intake pipe. MAF Sensor code gone & no more mouse nests.