I continue getting this error code on my truck. First I changed the spark plugs and the Service light went out for a short time. It came back on so I changed the plug wires and the light went out. Shorty thereafter the Service light came back on. I watched several You Tube videos and they pointed out I may have a worn distributor so I replaced the entire distributor assembly. The light went out for a short period of time but is back on. Any help is appreciated. The truck runs fine until the Service light comes on. It has about 175,000 highway miles on it and is not driven hard.