I have a 2001 Ranger Edge 3.0 v6 and it has been shaking a lot! It shakes when its idle in park and only gets worse when you start driving. When you get to around 55 mph and higher it feels like the whole truck is about to fall apart. For some reason when ever I come to a stop my speedometer also jumps from about 10-20 mph and just keeps bouncing and will stop when I start going again. The truck is also lacking power and at times it will feel like its hanging and ill have to stomp the gas to get it to accelerate and at that point the rpms will shoot up pretty high. its like its trying to get over a hump and once past it they will drop back down to normal. A few months back I got a check engine light and it ended up being a cylinder misfire so I went ahead and changed all the spark plugs and it went away but the shaking and stuff continued. Please help me out guys!