2001 expedition Check engine light HELp please

[Vicdad07]

I have a friend I am trying to help run this down on. The light was on and we did the 100000 mile service plugs, coils, oil and filter, and because the light had the o2 sensor fault both of them, air filter, fuel filter. The battery was disconnected and then the light was off. It came back on and had the voltage low on the o2 sensor and had a rough idle. I replaced the cold air idle valve. That did not work either. I checked with a scan tool and the fuel trim would be all over the place when it would idle rough ( only when cold). Then I called a few shops and al 4 said it would be a programming issue one said they could do it adn the other three said to take to a dealer. I got the vehicle reprogrammed today and it was driven home app 100 miles. The light is back on. Not sure the code but most likely the same o2 sensor low voltage.


Any assitance would be greatly appreciated. Very frustrating.

 

[5.0Flareside]

replace O2 sensors they're bad thats why All that work ya did and the code is still there..

 

[blacksnapon]

The codes would be helpful, but just looking, a lean condition will set a low voltage condition.

 

[Vicdad07]

additional Info

I did replace the o2 sensors. I also warrantied the driver side because the fault was still there. I checked the wires and they seemed all to be good. Everyone I spoke to said it was a dme issue so I had ford reprogram with the newest software. . The code was P0141 I have not scanned it again since the light came back on assuming it is the same code what would be suggested?

Sorry on delay I have been uber busy at work and no spare time.

 

[blacksnapon]

During testing the HO2S Heaters are checked for opens/shorts and excessive current draw. The test fails when current draw exceeds a calibrated limit and/or an open or short is detected. Short to VPWR in harness or HO2S.
Possible causes................................................................................................Water in harness connector.
Open VPWR circuit.
Open GND circuit.
Low battery voltage.
Possible component failures................................................................................................Corrosion or poor mating terminals and wiring
Damaged HO2S heater.
Damaged PCM.
Wiring.
Damaged HO2S heater.
Damaged PCM.

 

[Vicdad07]

Its got to be wiring i replaced that sensor and then warrantied it. feom the O2 conector where do the wires go? Is there a place i can access a wiring diagram?