I had the spark plugs and coil boots changed this morning, and here the photos of 113,000 mile spark plugs.

 

White tips = burning too lean/hot

Not too good but at least they aren't the worst I've seen.

 

What other signs might I see if my truck was running lean? My truck runs great, good fuel mileage, and never any engine problems noted.

 

rattling in the motor from the piston hittin the cylnder wall

 

With a 113K's on those plugs I think they look pretty good. You could always put them back in for another 25K But since you already replace them I'd would'nt worry about them for another 5-7 years, that's why you got all those 02 sensor's

 

They looked better than what I thought. Plugs have really come a long way with longevity.

 

Usually it's higher nitrogen levels in the exhaust but that's something to measure at emission time. But, as mentioned, periodic engine knocking, somewhat higher driving temperatures....it's not horrible for 113K, but they should be tan, not white. White just means it's burning too much air vs. fuel per mixture amount. Slight vacuum leak also but doesn't seem like it's anything to worry about. Some engines (even exact model copies) will run a bit more lean/rich from one to another.