list of power loss causes

I've got a 97 Mazda 626 2.0 that is lacking power especially up hill. Around 20 or 25 hp lost is my best guess. Its only stock at around 145. It has a small exhaust leak but that's all. I've replaced plugs and wires, distributor cap and rotor, both o2 sensors, checked both cats, reset timing belt, no engine light, replaced filters (air and fuel), serpentine belt, reset ignition timing, ignition coil, have excellent compression in all 4this cylinders, all accessories work perfect and no other symptoms like mpg bad starting or noises. Just want a full possibility list I was thinking fuel injectors but the car idles fine except from a worn engine mount. Never stalls always starts no leaks no overheating and shifts fine. Please give a list of any other possibilities. Its not the fuel pump

I have a 98 626 2.0. This is the best site I have found with lots of smart guys/gals. Sign up & post your question there.(in the right section) Maybe clogged cat?
http://mazda626.net/