What does this stand for? Most of the plug is black/brown and in some parts gray. I can pull pics if needed. Car's settings are rich, and timing is retarded a good amount. Im scared of detonation until I get tuned. Need to find out whats goin on so I can ease my mind. Plugs are NGK R5671A-8 picking up some BKR7ES-11's soon.

 

any grey means that it is going lean. if it is a nice brown golden color then you are pretty solid for AF. IF it is dark brown or black, then you are rich.

 

last time i changed my plugs..(3 weeks ago )they were showing lean mixture..but i dont see how when the car is stock with just a k&n drop in filter in the airbox minus the resonator...any ideas?

 

Its only gray on the tips. All the rest of the plug is black/brown. And im really rich and almost all the way retarded at the distributor. Why would I be showing lean?

 

Try those different plugs. as well as resetting your ECU again. If the computer doesn't know the changes in air flow and exhaust flow then it might be trying to overcompensate on things do to the different inputs its getting.