Engine light on again

Recently bought a used 2011 Ram 1500. Took it to a couple mechanics just in
case. No issues found. About 3000 miles later, including moving across
country to Colorado, still running fine. A few days later, engine light comes on
with no performance issues. Took it to a Dodge dealer and they stated oil
pressure was low and oil level was high, they didn't find any codes. 3 days
later, engine light comes on again when I'm entering the expressway at 60mph,
but this time it's blinking and the engine began to stutter with obvious loss of
power. Took it to another shop and they stated cylinder 2 misfired and the
spark plugs weren't even the correct ones for the truck. Spark plugs and
ignition coil replaced. Another few days later, engine light comes on AGAIN.
Same thing, entering the expressway and engine began to stutter once
again.Truck is back in the shop as we speak. What's going on? Any ideas?
Please help.