ive replaced idle air control , throttle positioning sensor, mass air flow sensor , air temp sensor , cam posotion sensor , clean all the way up to the intake manifold , now im throwing codes
p0171 system to lean (bank1)
p1506 iac valve duty cycle higher than expected
p0500 vehicle speed sensor a
p0401 exhaust gas recirculation flow insufficient detected
p0174 system to lean (bank2)

 

Which engine ? There's 4 gasers.

 

its the 4.2L v6

 

P0171 System Too Lean (Bank 1)
P0174 System Too Lean (Bank 2)

Set those aside for right now, but they are usually and air leak in the PCV system, or intake isolator bolts.

P0401 Exhaust Gas Recirculation (EGR) Flow Insufficient Detected.


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I suggest concentrating on the, -

P0500 Vehicle Speed Sensor (VSS) A. =Vehicle Speed Sensor Malfunction.
(Need a new one)

P1506 Idle Air Control Overspeed Error.
Was this a problem before replacing the IAC as well?

First.

 

i found the speed sensor for 19$ i will replace it tomorrow and the iac ive replaced it twice in past month (has lifetime warranty)

i really appreciate your response i have someone coming to look at the truck saturday and im trying to get it fixed by then

 

Were the P0171 and P0174 there before?

If they do not go away, save this link away for future reference.
https://sites.google.com/site/fordf1...P0171P0174-Fix