2021 GMC Sierra 5.3 3800 miles.
Had all the lifters replaced per TSB. After 100 miles the CEL is flashing again. Whats the next step? Engine replacement?
Took mine in today 2017 Silverado Z71 , they said thier was not a fix. The tech showed me how to duplicate the noise. He started to shake the bed of the truck left to right and the truck started to clunk. He said it was the axle shafts beating around. He also showed me on a 2019 trail boss. LOL