Won't go over 50 MPH!!! Help

[fireman31]

Hello I have a 96 Land rover disco SE. My car just all of a sudden won't go over 50. Its also sluggish up the hill. The rpms go up but it doesnt seem to want to go into the last gear. I checked the spark plugs, transmission fluid and oil. Its all fine, also I had someone check my catalytic converter and its not that. My fuel filter was changed a couple months ago. Any ideas on what this could be? Please help! Thx

 

[joey]

If it isn't the Cats, the could be the fuel pump.