Driving along in 3rd gear OD button off at 55-60 mph as I have done many times before and all of a sudden I lose power. I can barely keep going and a couple small hills almost done me in. Engine was running fine but it had no git up. I was almost home so I kept going as I didn,t want to be broke down on the road. There was no bad gauge readings-smoke nothing. So I make it home and go for another ride. Now everything is fine. Whats up with this do you think? 1999 A/T