Something is causing it to come on , either a small problem or a possible larger problem , but the fact of the matter is , it has come on and you should get it checked out.

 

That is one reason I don't use K&N filters, the oil vapors tend to screw up the MAF. The MAF is supposed to be able to burn the residue off the wires, but can only handle so much.

Disconnecting the battery will clear the code; however, if the trouble is still there the light will come on again. It is a good idea to read the codes before clearing them, because it may point to something important. and you want to take care of it before it gets worse.

As for the plugs, you didn't mention what engine you have, but the right side is a PIA, V6 or V8. Try from the bottom, you may have to drop the head pipes, which can result in broken manifold bolts, or remove the accessories from the right side to get a better line to the front plugs. There are special short plug sockets, open at both ends and shaped to take a ratcheting box wrench. They work good in tight spots, but I can't remember where I got them from