My echo hesitates on take off and it has a tough time getting up hills,on the highway it seems to wanna go but wont get up to 75-80

I think it could be the clutch or throw out bearing had the same problem I replaced the clutch and bearing worked fine good luck

Maybe catalytic converter

MyNiss. 88 fwd tk.was doing than after, tuneup.Ihad crossed vaccum lines on air breather.

If it is not going into overdrive or lockup it could be the fluid or an electrical problem. Some of the shifting is controlled by solenoids now.
You may have to get a transmission shop to evaluate it for you.

Tough to say if you can't duplicate the problem in the shop.
Only way to check the pump is with a pressure gauge.
Have you checked the computer for trouble codes ?

the very first thing you should do is have your fuel pressure checked. sounds like fuel filter or fuel pump.

mass air flow sensor its in the air intake pipe

Even though there is no check engine light I would still take it to Auto Zone to see if there are any stored codes.

EPA mileage figures are estimates, and seldom does it have anything to do with the real world, My new car is rated at 19 city and 28 hiway, it gets 22 MPG max. The only thing you can do is make sure the pressure in the tires is correct and run the recommened oil, keep the car in good running order.

This could the problem with on board computer please get it checked..............