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Replaced EGR and inspected contacts and harness.  Truck idle stalls intermittently with no pedal response.  The strange thing is when I adjust the pedal and brake with the adjust pedal switch the idle comes back to normal.
Vehicle: 2004 Ford F250 6.0

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by (13.4k points)
P0407 Exhaust gas recirculation sensor B circuit low

Circuit B  which is the GY/RD wire this is shared with the TPS and the ICP disconnect the EGR and retest
by (100 points)
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Disconnected the EGR Valve, same result.  Removed the EGR Throttle Plate, same result.  No improvement.  Truck surges at idle, at driving rpm truck surges slightly, sometimes at stopping idle about 650 rpm lose pedal response, or no pedal response and rpm drops to 500 or lower and dies out.  No check engine light, but code 407 and 488
by (13.4k points)
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P0407 EGR Sensor B circuit low
P0488 EGR throttle position range performance
You would think that the turbo is coked up. But a P0407 this is electrical especially when you adjusted the pedal and the RPM comnes to normal. What the APP and the EGR has in common is the Brn/ Wht  wire which is the voltage reference 5 volts then the Gry Red which is the signal return. You might just have a short in the APP. If you can repost I can send a detail of the wiring diagram By the way there a joke for this Ford and that is to carry a spare APP, or buy a dozen and keep it in the glove box as spare.
by (100 points)
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Disconnected and reconnected battery,  throttle plate out, EGR connected,.......... now only delayed pedal response and surging continues at Idle, stops signs and regular driving.  What's an APP? Thanks
by (13.4k points)
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You have a short to ground somewhere at the APP. the bron / wht wire is a refference voltage that goes to the EGR and is shared with the throttle position sensor, when you moved the APP you note it would idle better, it either the wire that has a short that cuts power to the EGR/throttle wiggle the wire see if you can duplicate it , the problem is not the EGR or  the throttle body somewhere at the APP it loses it refference voltage.
by (100 points)
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Found the Bron/wht, it does not move when the pedal moves.  Wire under the dash looks good and wire to EGR.  When the pedal moves only the accel and brake move the wires are stationary wondering when I actuate the motor it vibrates the pedal sensor, pedal sensors are an assembly and costly just to guess?
by (13.4k points)
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Circuit low codes are short whether it is internal or external. unless you can test the wire for its proper voltage. If you can clear the code and do a KOEO (key on engine off) and gather the code. just to find out who is causing the loss of voltage to the EGR/TPS/APP

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