My engine is slugggish between 30 and 35 mph and 50 to 55 mph. I have changed the plugs, the throddle position sensor, thought tranny shifting wrong so I have changed oil and filter. But no luck Anyone have any good ideas??

 

What year and motor? A tuner/programmer(Edge, XCal2, Superchips) would most likely solve your dissatisfaction.

 

Any time you replace or otherwise adjust the TPS, it needs to be recalibrated to supply the correct voltage output to the puter. Check your shop manual, it's a fairly simple adjustment. May not be the problem though.

 

The year of my truck is a03 f-150 5.4 If i unplug the computer will recalibate it right?? Anyway I I replaced the COP for the #4 cylinder it looks like it may have worked. We will see tomorrow when I drive during the day time temps??. Thanks for your help