csdangerous
Member
01 4wd with a 4.6 liter. Service engine light came on, code was 0401 EGT insufficient flow....still driving around, no power issues...light went off and hasn't come back on. Anyone else experience this ?
Check Engine Light/Intermittent
- Thread starter csdangerous
- Start date
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B
bedrck46
How many miles on the expy?
Have you ever cleaned the exhaust ports thru the throttle body?
P0401 - EGR Flow Insufficient Detected
Description
The EGR system is monitored during steady state driving conditions while the EGR is commanded on. The test fails when the signal from the DPF EGR sensor indicates that EGR flow is less than the desired minimum.
Possible Causes
Vacuum supply
EGR valve stuck closed
EGR valve leaks vacuum
EGR flow path restricted
EGRVR circuit shorted to PWR
VREF open to D.P.F. EGR sensor
D.P.F. EGR sensor downstream hose off or plugged
EGRVR circuit open to PCM
VPWR open to EGRVR solenoid
D.P.F. EGR sensor hoses both off
D.P.F. EGR sensor hoses reversed
Damaged EGR orifice tube
Damaged EGRVR solenoid
Diagnostic Aides
Perform KOER self-test and look for DTC P1408 as an indication of a hard fault. If P1408 is not present, look for contamination, restrictions, leaks, and intermittents.
INSPECT D.P.F. EGR SENSOR PRESSURE HOSES
Visually inspect both pressure hoses for reversed connection at D.P.F. EGR sensor or at orifice tube assembly.
Inspect both hoses for improper routing. Hoses should not be pinched or have dips where water could settle or freeze.
Inspect both hoses for leaks and blockage.
Inspect D.P.F. EGR sensor and orifice tube assembly for blockage or damage at the pickup tubes.
Is a fault detected?
Suggest you check the hoses to the DPFE sensor You may also need to replace the DPFE sensor. Before replacing check the EGR valve for proper operation and also clean the exhaust ports thru the throttle body by removing the throttle body from the intake and cleaning with throttle body cleaner
Have you ever cleaned the exhaust ports thru the throttle body?
P0401 - EGR Flow Insufficient Detected
Description
The EGR system is monitored during steady state driving conditions while the EGR is commanded on. The test fails when the signal from the DPF EGR sensor indicates that EGR flow is less than the desired minimum.
Possible Causes
Vacuum supply
EGR valve stuck closed
EGR valve leaks vacuum
EGR flow path restricted
EGRVR circuit shorted to PWR
VREF open to D.P.F. EGR sensor
D.P.F. EGR sensor downstream hose off or plugged
EGRVR circuit open to PCM
VPWR open to EGRVR solenoid
D.P.F. EGR sensor hoses both off
D.P.F. EGR sensor hoses reversed
Damaged EGR orifice tube
Damaged EGRVR solenoid
Diagnostic Aides
Perform KOER self-test and look for DTC P1408 as an indication of a hard fault. If P1408 is not present, look for contamination, restrictions, leaks, and intermittents.
INSPECT D.P.F. EGR SENSOR PRESSURE HOSES
Visually inspect both pressure hoses for reversed connection at D.P.F. EGR sensor or at orifice tube assembly.
Inspect both hoses for improper routing. Hoses should not be pinched or have dips where water could settle or freeze.
Inspect both hoses for leaks and blockage.
Inspect D.P.F. EGR sensor and orifice tube assembly for blockage or damage at the pickup tubes.
Is a fault detected?
Suggest you check the hoses to the DPFE sensor You may also need to replace the DPFE sensor. Before replacing check the EGR valve for proper operation and also clean the exhaust ports thru the throttle body by removing the throttle body from the intake and cleaning with throttle body cleaner
OP
OP
csdangerous
Member
148,000 miles. Runs strong. Very clean SUV in and out.
stamp11127
Full Access Members
Can be a common problem on vehicles with high mileage and has become a standard maintenance item when it occurs.
aircargoo
Full Access Members
stamp11127 is right. read my posts csdangerous.
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