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Egr excessive flow fault P0402 on 2001 Ford escape causing random misfire/ rough engine at any random speeds/idle. Replaced EGR Valve, selenoid and DEFP or whatever its called along with a new catalist. Any ideas?

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  • christian375 Sep 27, 2009

    I believe that is the same as the DEFP or whatever. Did that to already. I didn't have excessive EGR flow till I replaced the catalyst. No sure if the code is caused by the random misfiring or something else. The only thing that I haven't changed in the EGR system is the PCM and I doubt that it is the problem.

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Easy fix! I've had the same problem/headache and spent the same on parts. Replace your back-pressure sensor (it's easy to do-about $38-at Autozone or others) They can also show you where it is and how to do it. For a 2001 Taurus- part looks like a black box with 2 vacuum hose nipple holes and an electrical connection. It's definitely not your egr valve (costly!) I Should've asked my fleet service at work first rather than after. This repair consist of undoing 2 little vacuum hoses and an electrical connection clip and replace with new part in reverse order-DONE! Autozone will erase the codes with scan tool and your on your way. Ten thousand miles later and still no issues with mine! Good luck!

Posted on Sep 26, 2009

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Posted on Jan 02, 2017

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I have a 0402 fault code on my 16 hid xsara what does that mean?


OBD II Fault Code
  • OBD II P0402
Fault Code Definition
  • Excessive EGR Flow
Symptoms
  • Check Engine Light will illuminate
  • In most cases, there are no adverse conditions noticed by the driver
  • In some cases, there may be performance problems, such as dying at stop signs or rough idling, hesitation, misfires or lack of power (especially during acceleration), and a decrease in fuel economy
Common Problems That Trigger the P0402 Code
  • Excessive Vacuum signal or Electrical signal to the EGR Valve
  • The EGR Valve is defective and is opening too far or not properly closing
  • Lack of proper EGR system feedback to the computer from the:
    • Manifold Absolute Pressure Sensor (MAP)
    • EGR Temperature Sensor
Common Misdiagnoses
  • Ignition System
  • Fuel System
  • Oxygen Sensor
  • EGR Valve

Oct 31, 2016 | Cars & Trucks

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EGR faults


1.6b) Symptoms of faulty EGR
Associated OBD2 error codes DTCs: P0400 - P0409; P1403 - P1409 other common codes can include 'multiple misfire P0300'

The EGR has two possible fault modes either it is 1) open when it should be closed or 2) closed when it should be open. (See also DPFE faults)

'Open' faults
  • Erratic idling: 'hunts' at idle with erratic engine performance when running. This is due to the air ingress through the split diaphragm or the EGR valve being left open, either event compromises the intake manifold vacuum and in turn this interferes with the ECU's ability to deliver accurate fuel to air ratio for a given engine speed.
  • Sudden engine stall: In addition to the rough idle, a hot running engine when quickly brought to idle (after the car comes to a halt at a junction) can stumble and then stall. The engine will hesitantly restart immediately: this is significant difference to Crank and Camsensor error.

'Closed' faults
  • Misfire and 'pinking': if the EGR is jammed closed or the exhaust feed pipe is blocked (with baked on carbon deposits) the engine runs lean and very hot, so hot in fact that the fuel air mix in the cylinder can spontaneously ignite causing a misfire. The misfire if pronounced can, in turn, be detected by the engine knock sensors (P0300) leading to a 'check engine light' warning and reduced engine speed limitations.
Inherently diesel engines create more soot in the exhaust and as a result blocked EGR assemblies are more common in diesels than petrol engines.
  • Burnt Exhaust Valves. Prolonged exposure to excessively high ignition temperatures brought about by a blocked EGR system can lead to exhaust valves being over heated to the extent that they become distorted and so no longer seat properly. Poorly seated valves prevent good compression.
  • Surging: A sticking EGR valve can lead to an effect of rhythmic surging a bit like the MAF fault, especially in turbo charged engines. Normally on a warmed up engine the vacuum from the inlet manifold opens the EGR. If the EGR fails to open promptly the turbo can be subject to a slight boost. Extra fuel/air mix is pushed into the inlet manifold as a result, increasing pressure (decreasing the vacuum). Without vacuum in the inlet manifold the EGR closes again but if sticky only does so slowly. This may allow inlet gases to flow through the EGR into the exhaust manifold for a split second. There is a time lag in the sequence of these events leading the engine to surge in cyclical manner.
NEXT 1.6c) EGR how to fix



on Jul 15, 2011 | Mercedes-Benz E-Class Cars & Trucks

1 Answer

2002 buick Lasabrea custom service engine soon light code revi ew says multiple misfire detected


Multiple misfires can be caused by a few different things , intake manifold vacuum leaks , low fuel pressure , basic things like plug wires an spark plugs needing to be changed if hasn't been done already . How many miles on the vehicle ? If over 100,000 K timing chain an gear wear can also cause this . The powertrain control module (PCM) uses information from the ignition control (IC) module and the camshaft position (CMP) sensor in order to determine when an engine misfire is occurring. By monitoring the variations in the crankshaft rotation speed for each cylinder the PCM is able to detect individual misfire events. A misfire rate that is high enough can cause the three-way catalytic converter to overheat under certain conditions. The malfunction indicator lamp (MIL) will flash ON and OFF when the conditions for 3-way catalytic converter overheating are present.
If the misfire is random, check for the following conditions:
?€¢
System grounds


Ensure all connections are clean and properly tightened.


?€¢
Mass air flow sensor


A mass air flow (MAF) sensor output that causes the PCM to sense a lower than normal air flow will cause a lean condition. Try operating the vehicle within the Failure Records conditions with the MAF sensor disconnected. If the lean or misfiring condition is not present with the MAF sensor disconnected, replace the Mass Airflow Sensor Replacement .


?€¢
Damaged accessory drive belt or driven accessory


A damaged serpentine belt or belt driven accessory can cause engine load variations sufficient to set a misfire DTC.


?€¢
Air induction system


Vacuum leaks that cause intake air to bypass the MAF sensor will cause a lean condition. Check for disconnected or damaged vacuum hoses, incorrectly installed or malfunctioning crankcase ventilation valve, or for vacuum leaks at the throttle body, exhaust gas recirculation (EGR) valve, and intake manifold mounting surfaces.


?€¢
Fuel pressure


Perform a fuel system pressure test. A malfunctioning fuel pump, a plugged filter, or a malfunctioning fuel system pressure regulator will contribute to a lean condition. Refer to Fuel System Diagnosis .


?€¢
Fuel injectors


Refer to Fuel Injector Solenoid Coil Test .


?€¢
Water contamination in the fuel system can cause a single cylinder to misfire as well as cause a random misfire, refer to Alcohol/Contaminants-in-Fuel Diagnosis .


?€¢
EGR system


Check for leaking valve, adapter, or feed pipes which will contribute to a lean condition or excessive EGR flow.


?€¢
Extended idle


Excessive Open Loop operation caused by extended idling or short trip driving may leave deposits on the heated oxygen sensors. The deposits cause oxygen sensors to respond slowly to exhaust oxygen content, affecting fuel control and causing a misfire to be indicated at idle. This condition is not permanent. To determine if this condition is causing the DTC P0300 to set, review the Freeze Frame/Failure Records for DTC P0300. If the DTC P0300 occurs at high engine speeds, the condition described above did not cause the DTC to set. If the DTC P0300 occurs at idle or very low engine speeds and at engine coolant temperatures below 80?°C (176?°F), the condition described above is very likely the cause of the DTC to set. The deposits on the heated oxygen sensors can be eliminated by operating the vehicle fully warm at mass air flows above 15 g/s.

Jun 23, 2016 | Buick Cars & Trucks

2 Answers

98 Pontiac GRAND am


The plugs and crank sensor could have done it, but the TPS and idle air control would have nothing to do with a random miss.
A more likely cause is the ignition module or a fuel problem. You may have to wait until the problem is bad enough to kill the engine or you have more codes to check out.

May 20, 2013 | Cars & Trucks

1 Answer

My 2006 escape 3.0 idles rough but seems to run smooth down the road.engine light is on and shows code po402 excessive egr flow. engine starts fine when cold, but cranks for about 10 seconds unless you...


P0402 Exhaust Gas Recirculation Flow Excessive Detected 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
  • Solutions
  • 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.
    • Check the voltage at the DPFE sensor both at idle and when the EGR is open
    • Replace the DPFE sensor

May 04, 2011 | Ford Escape Cars & Trucks

2 Answers

I gotta 1997 toyota avalon its running rough i ran a scanner it threw two codes po441 an po402. i need help figuring out wat these codes are


Hi there osborne_shay,

Those codes refer to a problem with the drive train in your Avalon. Here is what the codes mean.


PO441-Evaporated Emission Control System / Incorrect Purge Flow
PO402-Excessive gas flow through the EGR valve

The cause for these issues are either that the components are faulty or they just need to be cleaned.

Mar 31, 2011 | Toyota Avalon Cars & Trucks

2 Answers

Po174


A P0174 lean code for bank 2 is the cylinder bank on the LEFT (driver) side of the engine on Ford vehicles with a transverse-mounted V6 engine and front-wheel drive. This code is not set on four cylinder engines (no bank 2).
WHAT A LEAN CODE MEANS
A lean fuel condition may exist if the engine is sucking in too much air and/or the fuel system is not delivering enough fuel. If bad enough, a lean fuel condition may cause lean misfire, a rough idle, hesitation or stumble when accelerating, and/or poor engine performance . Unmetered air can enter the engine through a vacuum leak, a dirty airflow sensor that is not reading airflow accurately, an EGR valve is not closing and is leaking exhaust into the intake manifold, an EGR valve that is allowing too much flow (because the EGR differential pressure sensor that monitors EGR flow is faulty and is under-reporting EGR flow).
If the problem is not enough fuel, the underling cause may be a weak fuel pump, restricted fuel filter, leaky fuel pressure regulator or dirty fuel injectors.

Dec 24, 2010 | Ford Explorer Cars & Trucks

1 Answer

Just replaced EGR hose & valve copver gaskets on 2002 Ford Escape 4WD. Did test drive, runs really rough & almost stops & cuts off. Any ideas?


OK, if you replaced the EGR hose, did you go all the way to change the EGR Valve? A stuck open EGR Valve can cause a rough idle and almost make it cut off.
Also, a vacuum leak on the EGR valve can cause a rough idle.

prev.gif next.gif Exhaust Gas Recirculation (EGR) Valve Removal & Installation 2.0L Zetec Engine NOTE: When the EGR tube is disconnected from the EGR valve, it must be discarded and a new EGR tube must be installed. The aluminum threads on the EGR valve must be inspected, and a new EGR valve installed if the threads are damaged.
To Remove:
  1. Disconnect the negative battery cable.
  2. Remove and discard the exhaust manifold-to-EGR tube. Use the following as a guide:
  3. Raise and safely support the vehicle
  4. Remove the splash shield
  5. Disconnect the EGR tube fitting
  6. Lower the vehicle
  7. Remove the air cleaner outlet pipe
  8. Disconnect the EGR tube from the EGR valve.
  9. Detach the vacuum line and remove the two retainer bolts.
NOTE: The EGR valve sealing surfaces are soft metals and easily damaged.
To Install:
  1. Installation is a reverse of the removal process. Carefully clean all sealing surfaces and install a new EGR valve gasket.
  2. Install a new EGR valve tube.
Detach the vacuum line (#1) and unbolt the EGR valve - 2.0L 02-04_escape_emissions_022.gif

3.0L (4v) Engine To Remove:
  1. Disconnect the vacuum line.
  2. Disconnect the EGR tube.
  3. Remove the EGR valve and discard the gasket.
NOTE: The EGR valve sealing surfaces are soft metals and easily damaged.
To Install:
  1. Installation is a reverse of the removal process. Carefully clean all sealing surfaces and install a new EGR valve gasket.
Detach the vacuum line (#1), unthread the EGR tube (#2) and remove the EGR valve bolts (#3) - 3.0L (4V) 02-04_escape_emissions_023.gif

Aug 02, 2010 | 2002 Ford Escape

1 Answer

1996 Honda Accord Rough Idle Even After tune up performed Changed spark plugs, distributor cap and rotor wheel along with all spark plug wires, changed fuel filter, air filter, spent $150 on fuel injector...


Perform a valve clearance inspection and adjust if necessary. Tight or sticking valves will cause a misfire or rough running concern. Note: Perform valve adjustment when the engine is stone cold. 4cyl: INT 0.26mm EXH: 0.30mm (V6 engine are hydraulic and no adjust necessary.) Also check for a sticking or stuck open EGR valve. For diagnostic purposes only: Remove the EGR valve. Place a business card over the EGR passage and bolt the EGR valve back on. This plugs the EGR ports and if the misfire goes away the EGR valve is partially stuck open and is defective.
Check for low fuel pressure. Check for low compression. Check cam timing. Check for a weak ignition coil. Also don't over look the possibility of worn or broken engine mounts which cause excessive engine movement and engine vibration. -hope this helps

Mar 02, 2010 | 1996 Honda Accord

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