P0108 code

I would hold the gas down at 5000rpm and it constantly pops from the exhaust. Runs rough. I pulled out brand new spark plugs and the tips of the platinum spark plugs were black.

So cleaning and reattaching the ground helped, the check engine light even went out. I drove it to work, when I got there the check engine light came back on and it went back to not starting when its warm. I did check the battery the other day and its good. I thought maybe a battery cable, or maybe the ground cable I don't know