My son has a 2006 F-250 with 6.0 101,000 miles. Check engine light came on and we checked the codes. One code was for the MAP/Baro (can't remember the code) and the other was P0470 (engine backpressure sensor). We changed the MAP/Baro Sensor and Backpressure sensor. MAP Baro code went away. Bps code went to P0470 and P0472. Cleaned up old sensor and put it back on and everything ran great for 1/2 day then P0470 came back. Bought another sensor and put it on, P0470 came came back. We have cleaned the EGR valve, checked the bps tubing for cracks and cleaned it. Where do we go from here??

 

Unusual that sensor replacement and tube cleaning didn't fix it. Is there a leak at the manifold maybe? Here is a little more info from the OBD operation summary(2003). May be of some help. I would try to verify VRef to sensor and VRet to PCM to check wiring next.


DTCs
P0470 – Exhaust Pressure Sensor
P0471 - Exhaust Pressure Sensor Range/ Performance P0478 – Exhaust Pressure Control Valve High Input
Monitor execution

Continuous (8ms)
Monitor Sequence



None.

Sensors OK

Exhaust Pressure (EP) and Exhaust Gas Recirculation Position (EGRP)

Typical Monitoring Duration

P0470 –Greater than 5 seconds. P0471 – Greater than 3 seconds. P0478 – Greater than 30 seconds.



Typical Exhaust Pressure Functional Check Entry Conditions:


P0470 – Engine off (mode = 0) or cranking (mode=1)
P0471 - Engine speed (N) is greater than 2800 RPM and EGR Position sensor (EGRP) is less than 10%
open.
P0478 - The engine is running (mode = 2)



Typical Exhaust Pressure Functional Thresholds:


P0470 - Fault sets if the Exhaust Pressure (EP) is greater than a 150kPa absolute. P0471 - Checks for a minimum Exhaust Pressure (EP) (10kPaG).
P0478 - Checks the exhaust pressure sensor (EP) by looking for a pressure above a specified value for the sensor (260kPaG).



Exhaust Pressure Functional Check Operation:
DTCs

P2263 – Turbo/ Super Charger Boost System Performance
Monitor execution

Continuous (8ms)

Monitor Sequence
None.
Sensors OK

Exhaust Pressure (EP)

Typical Monitoring Duration

Greater than 15 seconds below 800 RPM (N) and greater than 30 seconds above 800 RPM (N).



Typical Exhaust Pressure Functional Check Entry Conditions:


Engine is running (mode = 2).



Typical Exhaust Pressure Functional Thresholds:


14kPaG error versus commanded for 15 seconds when engine speed (N) is less than 800 RPM and 60kPaG error versus commanded for 30 seconds when engine speed (N) is greater than 800 RPM.




Typical Exhaust Pressure Sensor Circuit Check Malfunction Thresholds:

Voltage less than 0.03 volts for P0472 and voltage greater than 4.90 volts for P0473.

 

We were running some of the additional tests and friend recommended we disconnect the computer and see what happens. We did and drove it all day today without a code.

 

Ya sometimes Unhook the Batts turn On the headlights and Dump residual power Reset works

it may take a Few days Depending if it needs to fail more then 1 Drive Cycle

That's Good New if it stays Off