Two of my spark plugs in my 2013 Town and Country are wearing out much faster than the other four plugs. I have changed the coils for 3 and 5, I have also changed the cam shaft sensor. When those two wear down enough, there is a misfiring. For example, like when I'm going uphill and the engine is needing up upshift it starts misfiring until I press the gas pedal further to force it to upshift. I think I also feel it misfiring when the plugs are new but it's very light.