I had the code ran several times and it says missfire number one cylinder. They kill the check engine light and it comes back on the next time I use the truck. I had the oil changed and they used 5w20. I changed dealerships. They were the people that told me what they think is wrong. The lower the oil pressure gets the quieter the engine get until there is no noise at all except for normal. I do believe the dealer was using 10W30 but will have to call and hope they tell me the truth. I even thought about using 0W20 oil and see what happens.