2018 F150 w/v8, P0301 (Cylinder 1 misfire). Local dealer fixed. Code repeated within 75 miles. Engine light flashes for 30 seconds and then stops. New codes are P0301 & P0021 (intake camshaft position timing over advance bank 2). These codes have repeated 4x over last 3 weeks, each time flashing for around 30 seconds & then stops. Only runs rough while check light is flashing. Gas mileage down 2-3 MPG during this time. Causes? Opinions?
Also, any possible engine damage by running regular gas? Lots of clatter, especially when cold.
Many Thanks!!
~Greg