Took my 15.5 Denali to the local dealer (SE Michigan) with a CEL on 5/19. Diagnosed as a fuel injector issue. I had my injection system replaced in Feb'19 so, I was surprised. Dealer gave it back (and charged me $900) to me on 5/30. Drove it to work the following Monday, immediately threw another CEL and went into 'limp home mode'. Dealer has had it since, claiming they can't get parts out of Pontiac. I've opened a case with GM customer service but they're not helpful.
What would you be doing if you were me?
What would you be doing if you were me?