help 2 codes and truck wont run right

[alpine1jds]

my buddy has a duramax, either a 04 or 05 and it has 2 codes, P0207 injector ckt open cyl 7 and P2146 fuel injector group a supply voltage ckt open. all the truck has done to it is a edge juice with attitude and i removed it and the codes dont clear. when you give it gas it doesnt do anything and it idles rough. any ideas? maybe a bad injector? its his work truck so i need to figure it out asap. thanks for any help.

[BigRedChevy]

If it is a LB7 (8th digit in vin is a 1) then it is probably a bad injector. The injectors in the LB7s are covered under a 7yr 200000 mile warranty. If it is a LLY (8th digit in vin is a 2) then it may be the injector wiring harness. The have been known for the wires rubbing a through and causing problems.

[alpine1jds]

is the injector covered by gm for 200k miles???? and if it is in the harness is there a common spot that it rubs through? he was driving down the freeway and the light popped on and right after it started running like shit.

[JOSH-10]

if it is an lly inspect the wiring harness right at the ficm ( fuel injection control module )
the harness will rub and ground out on the braket above the ficm
where the harness turns and goes along the top of the ficm,
also those engine have problems with # 7 and # 2 injector connetor the pins in the connector would loose thier tension and not make a connection. you can buy new indivitual one from GM

[alpine1jds]

where is the ficm? thanks

[JOSH-10]

if you remove your air intake tube from the air cleaner to the turbo the ficm will be right under that.it a silver box ( 8" x 6" or so )
it will have 2 wiring connectors going in to the side if it. also it is right in front of the fuel filter ( to remove the connectors pull the tab on the bottom of the connector out and pull the connector staight out be careful not to bend and pins)

[jaydawg]

Stick with the connectors if it is a LBZ or LLY. Usually #7, #2 cylinders are affected. There is a GM BUlletin for this...repair kit is expensive.