My Check Engine light stayed on after starting my vehicle, so I checked the codes and got the dreaded P0301, P0304 and P300. I had not noticed any driving or performance issues as others had mentioned in their threads. After taking the vehicle to the dealer, they said that all 6 cylinders showed some ring problems. Anyone else had more than just cylinders 1 & 3 having problems? My vehicle has about 88000 miles and full synthetic oil used at each oil change.