Ive noticed lately that when i start to climb a log hill, the vehicle downshifts from overdrive and i can feel an immediate loss in power. when i press the gas the rpm's go up but the response in power isnt there. i just had the engine rebuilt about a month ago, as well as a new cat, o2s, plugs, wires, and cap. any suggestions on that what may be. I was thinking maybe that this may be a transmission issue. fluid is good, but could probably use a change. thanks for the help