they dont have much power. i did the airbox mod on mine which helped some http://www.fordrangerforum.com/how-s...ir-intake.html
1) did you or can you see if it thru any codes 2) Do you know maintenance history, ie, airfilter, pcv, plugs, wires, clean the maf if you have one you might have something else instead 3) run some injector cleaner thru the tank
2004 Ext Cab, 4WD, 4.0, Auto, 146k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 3/10/2016)
2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).