03 ranger 3.0. 4x2
Check engine light on loses power after 55mph. Up hill no power starts to cut out, makes a tinkling sound. Changed plugs,wires,fuel filter,ignition coil. Light is out. But no power up hill or over 55 mph. What do I check now

 

I would bet its a dirty mass air flow meter. get some intake cleaner and remove the meter from the airbox and clean it really well. then I would pull the cam sinc sensor and check for worn teeth on the oil pump drive gear. this is a huge issue with these 3.0l's. my friends truck just blew the motor on his 05 and after doing some digging the 3.0l eats the gears up. remember to mark where the shaft and pointer are and reinsert it in the same spot for timing. there are plenty of videos on youtube how to do this and they are the same(ish) on the Taurus 3.0l Vulcan. Ford Ranger 3.0L Camshaft Position Sensor