Only 1,200 miles after replacing all the coils and plugs the car developed a random ticking sound and misfire at idle. It would disappear even with the slightest increase in engine speed over idle. The ticking sound, which was coming from the #6 cylinder area, turned out to be sparking. I would see sparks at random near the ground bolt near #6 and also on other random areas on the RHS intake manifold. Here is a video clip. I was never able to capture the sparking on camera. I inspected all the grounds. They were in excellent condition. I even ran the car with the battery -ve directly connected to the alternator body. But it made no difference. I physically couldn't see anything wrong with the #6 coil or spark plug. I first replaced the spark plug, but that didn't do anything. So I decided to replace the #6 coil as well and that seems to have fixed the issue. I removed and refit the RHS intake manifold twice while troubleshooting. I've become quite good at it. Here are a lis...