I have a 2015 Chevy Silverado 5.3, when I only had 10k miles on it. I got 3 codes for misfiring on three different days. Of course dealer said they had to change all the plugs. I said you have to be kidding me, they changed $800 to replace. I don’t drive it a lot, because of my shoulders are artificial replacements. Well @ 12k another misfire and another $200 bill. I called delco for warranty they said sorry charle. Please help me out I’m going nuts, they said that I don’t drive it enough, I asked that they fail being parked in a my garage? Thanks your the best mechanic I know, I live in Crossville Tn.
What are the codes?
Many things other than spark plugs can cause misfires. You need to stay away from the dealer (as well as chain shops) and find a good independent mechanic that can do a proper diagnosis instead of guessing. (Unfortunately it looks like you're about 160 miles away from Scotty's Clarksville, TN location.)
This video will give you an idea of what it can take to track down misfire problems. It's a good bet that the dealer did not do anything like this.
they said that I don’t drive it enough, I asked that they fail being parked in a my garage?
they make a valid point. Cars don't like to sit around, or take short trips. It's not good for them.
And your Silverado has a weak engine, unfortunately. They're prone to lifter failure.
