OBD-II code 402 problem
Senior Member
Joined: Dec 2006
Posts: 43,526
Likes: 817
From: Joplin MO
A code P0402 most likely means one or more of the following has happened:
The DPFE (differential pressure) sensor is faulty and needs to be replaced
There is a blockage in the EGR (most likely carbon buildup)
The EGR valve is faulty
The EGR valve may not be opening due to a lack of vacuum.
With a P0402, it is common for people to replace the EGR valve, only to have the problem return. The most likely solution is to replace the DPFE sensor.
Read more at: https://www.obd-codes.com/p0402
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The DPFE (differential pressure) sensor is faulty and needs to be replaced
There is a blockage in the EGR (most likely carbon buildup)
The EGR valve is faulty
The EGR valve may not be opening due to a lack of vacuum.
With a P0402, it is common for people to replace the EGR valve, only to have the problem return. The most likely solution is to replace the DPFE sensor.
Read more at: https://www.obd-codes.com/p0402
Copyright OBD-Codes.com
Senior Member
Joined: Oct 2002
Posts: 7,295
Likes: 125
From: St. Louis (Out in the woods)
A P0402 is EXCESSIVE EGR flow detected, not "insufficient" flow. That means it's either detecting flow when there should be none or its detecting more flow than commanded.
Possible causes from the EVTM:
Possible causes from the EVTM:
EGR valve stuck open
Plugged EGR vacuum regulator solenoid vent
Plugged EGR tube
Slow responding DPF EGR sensor
Damaged DPF EGR sensor
Improper vacuum hose connection
Plugged vacuum hoses
EGRVR circuit shorted to ground
Damaged EGR vacuum regulator solenoid
Damaged PCM
Plugged EGR vacuum regulator solenoid vent
Plugged EGR tube
Slow responding DPF EGR sensor
Damaged DPF EGR sensor
Improper vacuum hose connection
Plugged vacuum hoses
EGRVR circuit shorted to ground
Damaged EGR vacuum regulator solenoid
Damaged PCM
Last edited by projectSHO89; Dec 29, 2019 at 05:23 PM.