2003 Montero sport just doesn't have horse power like it struggles up to speed

had it checked ..all good it felt like bad compression thats good ,valve cover gasket is leaking plugs have oil in them battery and alt replaced bank 2 sensor 2 replaced (o2 ) changed oil and filter plugs and wires are next with valvegasket thought throttle body ..cleaned that partilly EGR was caked cleaned it out part way check engine coded the (02) the idle was so low it would barelyrun read about dr tranny its keeping it running still rough idle not the timing the running has slightly improved with every thing fixed im at a loss and cant find anything that seem relevant this montero was terribly negelected its got 220,000 miles on it and still going hope you got something that helps....