Re: '04 F150 5.4L Running bad with no codes
What's the mileage on the vehicle? I wouldn't rule out the PCM unless you have super high mileage or do a lot off off roading in wet or muddy conditions. When was the last tune up performed (especially new plugs)?
I'd replace the throttle position sensor, idle air controller (IAC) and I'd get the mass air sensor checked out for proper operation. If the MAS is toast, the PCM won't know how much fuel/air mix to give the engine for proper operation.
If one or a few of these lower cost fixes solves the problem I suggest getting a transmission service done for better piece of mind.
'11 Ram Quad Cab 4x4 SXT 5.7L HEMI (stock); 48,500m
'06 Pontiac G6 GT 3.5L 220hp; 64,000m
'12 Chrysler 200 Limited 3.6L 283hp; 28,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!