MWR62

I have a 2019 Silverado RST 1500 with the 5.3L engine. I had the same problem at 28,000 miles I had the Service ESC, Service Brake System, and CEL light come on. It started running rough and shifting hard. I took it to the dealership. They replaced the spark plug in cylinder #7. Said the insulator on the spark plug was cracked. It ran fine for about 1 week and did it again. I took it in and they said the spark plug in #7 was not properly gaped. When I was driving off the lot it - all the warning lights came back on and it was running very rough (again). They kept it 3 weeks. They replaced 8 lifters, 8 spark plugs, wiring, and a solenoid. This concerns me. This truck is 17 months old with 28,000 miles and they went into the engine. What would that cost me if it was out of warranty??? I've had it back a week and now I have a service brake monitor light that just came on. I contacted Chevrolet and was assigned a case number (9-6392866522). I requested an extension on the warranty, but they could not offer one at this time. I think my engine issues are linked to the Dynamic Fuel Management. This is my 7th Chevrolet. I've never even looked a Ford F150's or Toyota's. But they are the contenders to replace this one.