93 Ford F-150, 4.9L, Code 179-Fuel Rich, Engine knocks upon acceleration,usually from 1st-2nd gear or under load. Does not do it all the time. The injectors are about 2-3 years old. The fuel pressure regulator, intake air sensor, coolant temp sensor, throttle position sensor, knock sensor, O2 Sensor, Radiator, PCV Valve, Several Vac lines and the thermostat are brand new. Any other suggestions on what the cause could be.



Optional Information:
1993 Ford F-150 4.9L

Already Tried:
O2 Sensor, knock sensor, thermostat, air temp sensor, coolant tenp sensor, throttle position sensor, MAP Sensor, vac lines,