Driving on parkway car looses some power & engine light comes on. Make it home & used the obd code scanner & it came back as rear #2 cylinder misfire. Took car to a mechanic & found spark plug coil broken in half. Plug was removed & it had no gap bar. Tried to install another plug to find out threads were damaged. What could cause this. Mechanic said I might have cylinder head damage. Mechanic never saw this before. Is this a defect from Honda?
The plugs had never been checked nor replaced and at 100700 miles, carbon buildup could have caused the threads to fuse together. When spark plug was removed, the fused thread resulted in the thread stripping.
You can try using a tap to rethread the hole and hope it works. Otherwise the head would have to come off for repairs. This can happen to any vehicle and during removal if the mechaninc had tried twisting in and out to loosen the spark plug to get it off instead of foecing it off directly, the damage might have been lessened.