Hey guys, having a small issue with the truck and am getting ready to try something but want to make sure I'm directing my limited funds in the right direction.

Truck does and has run great. This past summer, while hauling my slide-in truck camper, I noticed that the truck pings under load while climbing hills. So last month I changed all of the plugs and boots. Gaps were out by quite a bit. Changed them out and truck stills runs well but the pinging remains. Seems to ping more when the rpms are lower while climbing. For example, when climbing the hill on the highway, while the truck is in 4th but the rpms are around 1600, she'll ping, but once the tranny kicks down and the rpms jump to 2500-3000, pinging goes away.

Looking at the truck, I've been wondering if the truck still has the original o2 sensors (they sure look original). My truck has two sensors, one on either side pre-cat, nothing post cat. Before I spring for a pair of new motorcraft o2's, could old oxygen sensors cause the motor to ping under load? Any other thoughts? Thanks.