Sorry if this is not a correct post entry. But I have a 2003 WJ 4.7 HO 4x4 limited. I've been getting a knock sensor code for about a month now. Then today my engine is missing and jumping like it's outta gas. I even heard a belt squil briefly. I had to be at work so I couldn't tear down the intake manifold and dig in but I did find 2 pig tail couplers for the knock sensor. One was in use and the other was not plugged into anything. Should I have 2? I know I have two sensors that bolt on but I was confused about having 2 couplers! Please help it's my DD and only way to go.