my gas gauge isnt workin and my engine has trouble turning on so i think its the temperature sensor... where is that located under the hood and is it hard to replace?

 

Ummmmmmmmm....Are you positive about this? Are you running a CEL? I have a feeling its a Fuel Relay...There are 2 temperature sensors..coolant and Intake Air Temperature...IAT tells the computer when its warm to give it less gas because its now warmed up.