2001 ranger 4 cyl 5 spd the engine starts fine and idles good also rev's up but when you try to go it just looses all power after you let it warm up maby 10 minutes you can drive at highway speeds 65+ but it is still the same after you stop for a couple of minutes, what could it be

 

probably a plugged catalytic converter

 

will it still run at hyway speed if the converter is clogged

 

if it was a clogged converter it wouldnt rev up...it would only idle fine