Egr P0401/p0402
#16
12-05-2007, 01:58 AM
Sorry I didn't see your post -
DPFE - There are three types.
Call the dealership , you may have to swap that one out. Explain your concerns as you have in this thread. Both plastic units had problems.
All DPFE Sensors must be replaced with the same units. If your old Sensor is "Plastic" then you need the correct plastic one . There are two which look completely different from each other .. Compare the one you have on the vehicle to the one you purchased from the dealer .. If they look the same , you have the right one.
If there is an "Aluminum" unit on your vehicle , it must be replaced with the same type aluminum sensor.. That's important or it will not work properly.
PO402 = Poppet Valve Stuck Open -
Not a DPFE problem most likely. You need to suck test the EGR valve to test. If you don't have a vac tester you can test the 402 this way.
Start your vehicle, while @ idle disconnect the green vac line from the EGR valve. Find a piece of hose about 3' long that you can plug into the EGR valve in place of the green line. While your Vehicle is still at idle , suck on the hose like you were drinking a milkshake. Does your idle change? does it want to stall? If so , then the EGR valve is good . If there is no deflection or change in idle speed your EGR valve needs to be replaced..
If it passes this test , your EGR ports are dirty . Once you pull the TB and Elbow , clean the ports leading to the EGR valve and all others since your in there .
With the 402 code , those steps are performed first before replacing the DPFE. A 401 code is most likely the DPFE, NOT the 402 code.
Here's some GREAT!!! illustrations for you to go over -
http://www.fordscorpio.co.uk/egrmonitor.htm
DPFE - There are three types.
Call the dealership , you may have to swap that one out. Explain your concerns as you have in this thread. Both plastic units had problems.
All DPFE Sensors must be replaced with the same units. If your old Sensor is "Plastic" then you need the correct plastic one . There are two which look completely different from each other .. Compare the one you have on the vehicle to the one you purchased from the dealer .. If they look the same , you have the right one.
If there is an "Aluminum" unit on your vehicle , it must be replaced with the same type aluminum sensor.. That's important or it will not work properly.
PO402 = Poppet Valve Stuck Open -
Not a DPFE problem most likely. You need to suck test the EGR valve to test. If you don't have a vac tester you can test the 402 this way.
Start your vehicle, while @ idle disconnect the green vac line from the EGR valve. Find a piece of hose about 3' long that you can plug into the EGR valve in place of the green line. While your Vehicle is still at idle , suck on the hose like you were drinking a milkshake. Does your idle change? does it want to stall? If so , then the EGR valve is good . If there is no deflection or change in idle speed your EGR valve needs to be replaced..
If it passes this test , your EGR ports are dirty . Once you pull the TB and Elbow , clean the ports leading to the EGR valve and all others since your in there .
With the 402 code , those steps are performed first before replacing the DPFE. A 401 code is most likely the DPFE, NOT the 402 code.
Here's some GREAT!!! illustrations for you to go over -
http://www.fordscorpio.co.uk/egrmonitor.htm
Last edited by jbrew; 12-05-2007 at 03:00 AM.
#17
12-05-2007, 02:44 AM
Testing PO402 (Stuck Valve)
The "suck test" will confirm proper EGR valve operation..
EGR Valve -
A conventional vacuum operated EGR valve is used on the Scorpio. The valve increases or decreases the flow of exhaust gas into the inlet manifold and this is by a diaphragm operating on a pintle which is connected to a poppet valve. When no vacuum is present, the spring keeps the poppet valve closed. When the EVR allows sufficient vacuum to the EGR valve, the vacuum pressure overcomes the spring and the poppet valve opens, but as soon as the vacuum pressure is reduced spring pressure closes the poppet valve again.
The "suck test" will confirm proper EGR valve operation..
EGR Valve -
A conventional vacuum operated EGR valve is used on the Scorpio. The valve increases or decreases the flow of exhaust gas into the inlet manifold and this is by a diaphragm operating on a pintle which is connected to a poppet valve. When no vacuum is present, the spring keeps the poppet valve closed. When the EVR allows sufficient vacuum to the EGR valve, the vacuum pressure overcomes the spring and the poppet valve opens, but as soon as the vacuum pressure is reduced spring pressure closes the poppet valve again.
Last edited by jbrew; 12-05-2007 at 02:49 AM.
