Duramax LMM codes and injection
 

Completely stock 07 Lmm Max 4x4 with 200,000 miles it had a injector knock on #6 that was initially diagnosed by the previous owner as a rod knock when I purchased it. I have checked the harness but with all the codes its not isolated to the knocking #6 injector. Any thoughts?

Code P244b- DPF over pressure
P0300- Random missfire
P0206- Open injector #6
P0208 Open injector #8
P0303 Cylinder #3 missfire
P0301 Cylinder #1 missfire

I am also seeing fuel seep out around the EGR valve and am assuming its from over fueling of the stuck injectors.

I un-hooked #6 injector and the knock is gone. I have checked for harness rubs and cant see anything but if there is a prone area on the lmm please let me know.

I am just trying to gauge if I should tackle it myself or take it to a shop if I am going to need a tech II to diagnose the codes. I am hoping I can find the cause, swap the bad injectors, change the fuel contaminated oil and take it in to have the injectors calibrated saving me money.

Thanks,

Terry