| Was it running ok before the new plugs?
Reason is, the hex on the specified NGK's is too low and using a conventional plug socket, you won't be able to tighten the plug up fully. Even a cheap box spanner is too thick walled.
The profile of the plug cavity at the bottom pushes the socket off the plug....
Wish they'd try and fit them before spec'ing them | 
Hybrid Mode
