It all started when the cooling fan started running a lot more than normal and the temp guage was reading low coolant temp. I have changed the coolant temp sensor and thermostat, and have removed the ECM and cleaned the terminals, cleaned the terminals of the coolant temp sensor connector, and looked at the intake plenum for leaks. Although the temp guage is working normally and the fan now runs normally, I get an occassional single misfire with rough running for a second or two and then the P0116 code lights up on the dash. There are no other codes. I'm running out of things to look at, anyone got an idea?

 

Could be bad sensor.

 

I thought of that too, but the new one I put in solved all of the symptoms (except the light), do you think it could still be bad?