P0401 Ford - explorer

Question

My 2008 v6 4.0l Explorer has the service engine light On. Multiple codes appear- 0401, 0442. There is vibration in the transmission system, unstable RPM (down to 500 instead of 750) sometimes stalls on the run when release the accelerator, low gears (2 & 3) give high revs before shifting, the noise rise at the clutch fan. The noise/revs gets excessive high when the AC is switched on. When the AC is switched on the RPM goes down and jumps or the car hols itself back on the run.

I have changed all the required parts like canister valve, EVAP fuel hose, EGR sensor, throttle body etc. Still facing the problems. Plz help

Answer 1

P0401 Exhaust gas recirculation (EGR) insufficient flow

P0442 Evaporative emission system (small leak detected)

Unstable RPM and and no EGR system , this is more of a vacuum leak condition, affecting the EGR perfromance. As for the cooling fan noise and the transmission  , you may have a transmission that is slipping, or flares. Scan for code for the transmission system .

 

 Here is a vacuum line for a Ford that is right near the battery, what happened is battery corrosion has rotted the vacuum hose line, One of the vacuum line is from the intake manifold and the other will go to the EGR , the fuel pressure regulator,These break in the hose cause a high RPM condition.

 

Heres the vacuum line fixed as it is supposed to be.