check and make sure the barometric pressure sensor is hooked up (it compensates for altitude) its a small black(1.5x2 inch) plastic box between airfilter housing and fender .many people disconnect this as it sometimes makes cars run better ,usually richer at sea level. I drove from Vancouver to Calgary today. Had a blast heading to Kelowna early in the morning with no traffic. Car was running great until abround Golden when she started to sputter and hesitate when I accelerated. I was in 5th and she would not go past 5000 rpm. At first I thought maybe I had a fuel line problem but once I got over Rogers pass and into Calgary she seemed to be running fine again. Is it possible that the air was too thin up on the pass? To me that sounds ridculous but that is the only thing I can think of. Any thoughts on this would be apprectiated before I take her to the dealership.