04 5.4 99,000 miles Changed fuel filter and both oxygen sensors, light came back on at stop light seems to labor at 500 rpm before idle kicked back up. fuel economy seems to be suffering also, any thoughts or is it time for the shop.

 

Have the plugs been changed?

 

Did you disconnect the battery and clear the KAM? If not you will need to.

 

you may have also been to late with that filter...pump may be damaged.

 

Sounds like you have a vacuum leak past the maf sensor. Anytime you have unmetered air entering the motor you lean out the fuel mixture. Once the computer has tried to adjust it with the fuel trims and cannot account for the extra air it will set your trouble codes. If you had lack of power or fuel pressure problem the code you would set would be a fuel rail pressure code. With the engine running, listen for a whistling sound. Ford just put out a recall for the vacuum booster line coming off at the back of the intake manifold. If your brakes also feel stiff, this could be your problem. Good luck

 

Just what I needed more bad news. Intake manifold has a vacumn leak and for $600 you can put it back the way it ought to be, looked at vacumn booster and 04 is not in recall, but by the looks of it should be,surface of hose fell off when i touched it rubber has definately lost its give, hands turned black like I poured graphite on them.

 

Is this the infamous PVC hose?