I was passing a line of vehicles when a semi started over into my lane. I hit the gas, to avoid being hit by the truck. When I did warning light on my vehicle appeared on the display. I lost speed and immediately heard a loud knocking from the engine. I was on an open 4 lane highway and knew there was a dealer close by. I drove to the dealership, I left the vehicle running so they could hear it. The service tech told me they had seen ‘several’ vehicles in with the same problem with the 5.3L . I left the vehicle there and was given a loaner. They told me the lifter had gone bad when I sped up quickly, and the camshaft was damaged. Further research by me has discovered a lot of vehicles have this same issue due to the active fuel management system. I chose not to pay Chevrolet $7000 to fix the engine, and currently have it in a private shop being repaired. A less experienced driver may have slammed on the brakes or swerved and caused a major accident. My vehicle did slow down on its own, but I was able to keep control and safely maneuver to the right lane.