Hey everyone I have a 2007 Crew cab frontier 4x4 le 102k miles. It was a gift from my recently deceased father in law but is having issues. It starts up just fine but has a put put sound they doesnt change. It has thrown the p0300, and p0463. It has new plugs but they are already gunked up and covered in gas. The cats outer shell jas been split on both prime converters. I would really appreciate any input as too how to fix this issue so I can get it back on the road.