losing power when going 65mph

Hi everyone!
I have a 1995 Ford Contour and I'm having trouble with it since going to the smog shop to get the car smogged. I had to replace the battery and the alternator but now when I try to drive 65mph on the freeway it starts losing power. I know I need to replace the serpetine belt because of all the wear and tear. Is the catalytic convertor going out and that is why I'm not getting any power past 60mph or what? I have over 102,000 miles on this car. Any help or suggestions would be appreciated. Thanks.

your catylitic converter has nothing to do with your electrical power. If your belt's visually worn than you should def replace it... that's kinda dangerous and could affect how much power your alternator is putting out. I can't imagine why it would change at 65 though.

If you are losing power at freeway speeds I would suspect the catalytic converter first. But i would check your belts if you haven't inspected or replaced thouse recently. But around 100,000 miles those things usually need attention on some cars. I know it did on my 2000 Jetta.

If the catalytic converter is going out, sometimes the "filling" which traps the gasses will shoot out of the cat and into other parts of the exhaust system (like the resonator or muffler) and plug the exhaust, causing too much back preassure, and robbing power from the engine. After a few miles, sometimes it will build enoegh pressure to clear itself out and you will see a cloud of smoke behind you.

Check the belts, check the exhaust system, and check your spark plugs.