ok i have a 2001 kia sportage it starts fine and idle normal but when you drive there is a definate power loss!!! going over 3000 rpm is a problem the car will not go faster than 50 mph and takes alot of effort ! going up hills is a near impossible we took the cat of and same thing no power , i was told there are 2 cats????? also change the belt 2 years ago and ran fine after also change the filter (fuel) but we take off the air cleaner and the is power gain so at this point i have no idea any ideas????