Yesterday while at a drive through my 08 Envoy Denali started idling odd. My check engine light came on the started blinking. I took it to autozone and they told me the code was P0300, multiple misfires. I was able to drive it to a shop and drop it off. Mechanic looks at it and says #! and #2 Cylinders have NO COMPRESSION??? None, and the spark plugs look as if they have been packet in mud. Has anyone ever experienced this? They said I would most likely need a new engine. I'm hoping it just a nightmare I'm going to wake from soon.