I have a 2007 Silverado Crew Cab, 2WD 5.3L with 45000 miles. Since new, it has not had an issue running 87 octane gas, but lately it has been pinging under moderate - full throttle. I tried higher octane gas, and though it pings less, it is still there. This truck has never worked hard a day in its life. I have thought about replacing the spark plugs, but I have had other vehicles run much further before needing replacement and doubt that this could be the problem. Could I have a bad knock sensor? If so, would the check engine light come on? I do not wish to continue spending the extra money on 89+ octane gas.