2005 LLY knocking still

[BIG UGLY]

I took it to be diagnosed and they told me it was the ficm and injector 1,2, and 3 where possibly faulty. I bought a used ficm and installed it and nothing changed. Could the old one have damaged the injectors? And why those three? I'm getting very frustrated and don't wanna keep throwing money in it. I looked for shorts in the harness and haven't found any yet. Is there a place I should look for one that would cause those three injectors to not work right? I did try disconnecting injector 1,2,and 3 one at a time and starting the truck but I got a completely different result when doing that.

[rapidoxidationman]

What codes have been thrown?

[Kennedy]

The LLY's sure seem to have a lot of wiring issues. Most commonly a wiring issue particularly near the FICM.

[BIG UGLY]

P0201
P0202
P0203
Malfunction in circuit ficm injectors 1,2,3
I can't find any shorts. Can this be caused by transmission oil gettin into the connectors of the ficm? My cooler busted and sprayed all over the engine compartment a couple months ago. But it had no trouble till very recently.

[BIG UGLY]

I just cleared the codes and tried again to find a short with no luck. To get the truck to throw me a code, do I have to drive it or let it run a while? I started it up for a minute and no codes. It sounds the same. Thinking about trying to get the problem injector or injectors tested but I need to be sure which injectors are ruining my day.