When I passed the truck I lost power and it ran really rough an i made it to work going 5 miles an hour,I towed it home and changed plugs,wires and cap and rotor.It started but still same problem.the fireing order is right.I tried it again today and foweld my plugs.I put new ones in and it still runs very rough my check engine lite came on when it first happened and my computer said it was missfire on cylinder 5 is it my coil or can someone help me figure it ou without spending money