My check engine light came on and the engine started running rough, so I changed the spark plugs. Still running rough. Code says cylinder 3 misfire, so I disconnected coil and the level of roughness didn't change. Switched coils with another cylinder to confirm problem was the coil, but nothing changed. So the problem isn't spark plugs or coils. I'm thinking perhaps it's the powertrain control module, so I want to first reset it to see if that fixes the problem. But I don't know where it is. Can someone help me? Any advice of what the problem could also be?