P0304 MISFIRE ON CYLINDER 4

The old ones were suppose to be SC16HR11, i couldnt get SC16HR11 locally same day, they only have SC20HR11. so thats what i installed. the Old ones originally looked like the new ones. what you are seeing are really worn out. I guess I'm better educated now . you can see the discrepancy. even price is not a good indicator of it being genuine or not. here is a full pic.

 

True iridium plugs are usually good for at least 100,000 miles with little erosion. The plug on the right is suspiciously and excessively worn. I would say that it’s a Chinese clone (fake). Also, the plug gap appears to be incorrect from the day it was installed. It’s obvious that the gap a has been tamper with. These plugs should be pre gapped from the factory.