Hoping some guys can chime in and help me. My truck has had a misfire in the upper rpm range for sometime now, it's worse with regular fuel. It popped the p0300 code on my way back to school 2 weeks ago, pulled over cleared the code and it was fine for the rest of the 150 miles trip.
Now I have downloaded some plugins on my torque app which allows me to see the current and history of misfired on all cylinders and I have current random misfires on the whole left bank cylinders 2,4,6,8. They are not severe enough to effect drivability or pop a code put my torque app is still picking them up. After popping the hood am inspecting I noticed that on that bank there is a considerable amount of oil residue built up along the bottom side of the valve cover. Haven't pulled the plugs but could a bad valve cover gasket be dripping oil onto my plugs causing the slight miss on that whole bank? Considering its the whole bank and my fuel trims are still within spec I think I have ruled out air or fuel issues. Any thoughts?