I have a P0204 and P2149 codes in my truck and it's running terrible. After research, I think it may be injector #4 or my wiring harness to 4,5,6. Does the fuel line and feed nozzle in the side to the injector need removal before I can pull out the injector? Can I just lift off the solenoid carefully off the top of the injector and put a new one on if it tests bad? Anybody know off hand the torque specs for the valve cover and the two injector bolts? Maybe a dumb question but I'd like to fix it myself if possible. Thanks, Herb