Okay, so im driving back home to virginia beach from richmond. I was doing a steady 75-80mph the whole way home until i hit traffic close to hampton. I noticed after awhile my air to fuel ratio at the beginning of the trip would sweep from rich-stoich-lean-stoich-rich etc. (back and forth like it should). When i hit the traffic and stopped then got back up to speed eventually it was showing mostly only lean and occasionally stoich. I wasnt running hot, as the engine temp needle wasnt even close to half way. Am i just being paranoid or what? Ive never seen it only stay in lean just cruising... is there a potential problem?