Gutz66

Hello, Hoping to find some help here as I am at my wits end. Threw a code P0030 originally and then a P0300. I assumed the O2 sensors were up for replacement due to very high mileage I have. I ended up replacing both the upstream and downstream sensors so that rules them out. Once I did that, truck ran good for about 5 min. Started to stumble and lack power and poor idle. Now I have P0300, P0500, P0030, P0031, P0135, P0137 and P0172. I had already replaced the fuel injectors, fuel rails and plugs about 3 years ago max. My INNOVA 3160e scanner is not pointing out a specific bank for misfire at this time, just generic codes. Any thoughts out there? Hate to take it to the dealership but I am starting to run out of options. Thanks

Update: Basically the entire front end had to be removed to access the header panel. Not difficult but a pain none the less. Bumper cover, grille, fuse box, battery and housing, wiper bottle, fenders, hood, radiator/AC condenser along with all of the wiring and other related items to the front clip.

Any updates on your issue?

Looking for some references on how to replace the header panel on my 2014 GMC Sierra SLT 1500. Been looking all over and have been unable to located the procedure to remove my damaged piece. Silverado is not the same as the Sierra and that is all they show on youtube. Thx