I have a 2000 STS and my service engine soon light is on. The code says the #3 cylinder is miss firing. I've changed the sparkplugs, coil and injector and it's still miss firing and reading the same code. Does anybody have any suggestions? The car idles a lil rough but drives fine when on the road. I can definitely feel and hear the missing!
There is a spring in the boot, make sure it is intact, carries the current from the ign module to the plug. You can swap the coil pack/ignition module between the heads and see if the Po3xx follows it.