Well, get to put this issue to rest. Final update for anybody interested. Issue was for sure a bank 1 injector failure that i was told by a GM Engineer is a known issue with the full size chevy and gm pickups. After being told injector was backordered, i took to social media and received a reply in minutes from Chevy. They asked for my vin to investigate. With in 5 minutes they replied and gave me a case number and said it has been escalated. Was told i would receive a call the next day from my case rep. Was also asked to only communicate with her so things didnt get confused. I did receive a call on May 5th from case rep, she told me they are trying to locate an injector and they would pay for a rental. She also advised me to tell dealer to do trailer brake recall while they had it. She stated she would call me back on Tuesday May 9th. So, on Tuesday i stopped in dealer to tell them to do trailer break recal which i was told they had already done it the day before. Then he informed me that my injector arrived that morning and the technician was installing it as we spoke. I asked him how it went from backordered a week prior to having it on site. He said he didnt know. That it just showed up and was overnighted from somewhere. Later in the day, my case rep called to see if i was updated by the dealer and filled her in on everything and asked her how they got the part. She explained that when there is a backordered part and a case is opened and escalated, they start looking to see if any dealers have the part and if they are willing to give it up. Luckily a dealer had one , gave it up and overnighted it. I got a call on May 10th that the truck was ready and that there also was NOT an issue with the transmission. Apparently a tech accidently wrote that on my slip. I picked the truck up and everything has been good since. Case rep followed up with me twice since getting truck back and last contact she informed my that gm has credited my gm account with 50,000 points which equals $500. Case is now closed out.