I have. 2004 Nissan 350z 169000 miles automatic I drove to Tennessee from Texas when I arrived I notice a bad misfire I pulled out my scanner it read p0302 code so I took the coil pack inspected the spark plug looked fine swapped the spark plug and coil to the cylinder next to it I notice the spark plug in the cylinder next to it was white also been noticing my engine seems hot not overheating or coolant issue but runs hot swapping them out now gives me a code of p0300 not sure what is going on I don't think I have any vacuum leaks from what I can tell I can try the old cigar tricks this weekend but not sure if that's the way to go I maybe taking it to a mechanic but I would like some input maybe you know something to look for
Okay if the plugs are white it is running too lean which will cause misfires. Generally running to lean if it's only a few cylinders and not all of them would be a problem with the fuel injectors on the cylinders that are running White.
