I rarely drive over 50mph but over the holidays I drove freeways at around 70. While driving I noticed that it began to hiccup while climbing hills at speeds above 60. The truck is well loved and due for a tune up and oil change which will be done this wend. I plan on spark plugs, fuel filter, oil/filter....no light on but plan on having codes ran...any suggestions so my mech doesn't tell stories of grandiose repairs?