MAF and other sensors, Coil Pack

[bigboyisme]

Does anyone know what sensors can be cleaned and with what?

I noticed a cylinder was missing today and started pulling plugs off the coil packs to find the missing cylinder. As I did so, I noticed sparks jumping all over the place from the wire I pulled off the coil pack, is this normal? Or should there be no arcing at all? It turned out to be the #4 cylinder that isn't firing all the time. No codes or cel.

[86TATpi]

You may need to check that coil pack to make sure it's still ok. Also check compression on the number 4 cylinder.