As of late My 89 ford bronco (4.9,6cyl,4 speed)has been giving me problems!Every time I take off it has alot of hesitation and lack of power going up hills!It sounds like I might be sucking in air from the lower intake but not sure!could it be that I need to put in new intake manifold gaskets!?I hoping it is not the o2 sensor!I just cleaned and put on a new throttle body gasket!I also took one of my spark plugs out and notice that it looked like they were heated up!I just put them in last summer and I didn't use the truck this winter!Any Ideas?