Code 401 ecg valve ok electric vale ok what else could it be

This is a frequent Code for many motors. Let me explain how this works. Think of the EGR valve being in the middle of the flow of Exhaust gas. At one end is the exhaust flow coming past the ports inside the intake manifold, at the other end is the measuring device for this flow.

If the exhaust flow is blocked inside the Intake, there is no flow to the EGR, and no flow past the measuring devices at the end. Many times you will need to pull the Airhorn and clean the well beneath the gasket of the Airhorn. This will restore the flow.

On the measurement end of this system, there are 2 Vacuum lines that fit on the DPFE switch connected to the EGR valve. The flow is measured inside the DPFE and if the metal tube is rusted that the Vacuum lines plug into from the DPFE, the readings will trigger the Code 401 for low or insufficent flow. The DPFE switch itself can short out and give the same Code.

On some motors there is a switch in front of the Airhorn and it has Vacuum lines going to the EGR also. This switch usually gives a Code 404. So you will not get a Code 401 from this front switch.

After you clean the Intake or change a rusted metal line, whatever the case, you will need to clear the computer of its Codes. I hope you find my solution very helpful in the repair of your Explorer.

You need what is called a DPFE sensor will either be silver metal, or if it has been replaced black plastic. IF its a 4.0l engine then its on the drivers side of the intake with two hoses going from sensor to exaust pipe. IF this is a 5.0 V8 then its on passenger side behind throttle body. Basic part number is 9J460