Rough idle and check engine light turned out to be the dreaded lifter failure. Dealer states the current TSB only allows them to replace lifters on one bank and not the whole engine.

Has anyone had multiple lifter failures and had to go back for the second set?

Luckily no bent pushrods or other damage with this episode.

 

2020 Silverado 5.3- Knocking, check engine (emissions warning), Service ECS, parking break. Took it in this morning and haven't gotten the official diagnoses yet, but the technician said this combination sounds like lifter failure. I bought the truck several months ago with 8k. It's now at 17k. Seen other comments that this may be a common flaw of the 2019s and later.