Well the truck has 113k on it I was told at 96k when i bought it had been tuned..but who knows..i should change them....probably the originals....Any idea on plug recomendations. I like the idea of fuel efficient ones..like split or bosh..they have that one with the oxy sensor and some guarantee/....but does it really matter? What of factory orig ones?

What is A COP?

Thanks

Doug