I have an 04 lly. Truck was sitting idling when it started knocking and engine light came on. Shot out p0201 p0204 p0206 p0207 p2146. I read that it may be a loose connection but can't find anything. Also read it may be fuel injection control module. Help please!

 

do you have the #2 and #7 pigtail harness update? if so youll notice a bracket holding the injector harness at #7. If not that is more than likely your issue. Unplug #7 connector and look at the end, if it has some tan looking dust at the terminals its shot. Some times you can unplug and replug it and start truck and itll be fine but, it will act up again. You are getting multiple codes because when one inj. circuit fails the ficm shuts off corresponding cylinders (a pair on each bank) and will set the p2146 code in your case.