Hi,
HOW TO INSPECT EGR VALVE
Before attempting to troubleshoot or repair a suspected exhaust gas
recirculation (EGR) system on a vehicle, the following conditions
should be checked and be within specifications.
If one or more of these conditions is faulty or operating
incorrectly, perform the necessary tests and services to correct the
problem before servicing the EGR system.
Before attempting any tests of the EGR system, visually inspect the
condition of all vacuum hoses for kinks, bends, cracks, and
flexibility. Replace defective hoses as required. Check vacuum hose
routing. (See the underhood decal or the manufacturer's service manual
for correct routing.) Correct any misrouted hoses. If the emissions
system if fitted with an exhaust-gas-recirculation valve position (EVP)
sensor, the wires routed to it should also be checked.
If the EGR valve remains open at idle and low engine speed, the idle
operation is rough and surging occurs at low speeds. When this problem
is present, the engine may hesitate on low-speed acceleration or stall
after deceleration or after a cold start. If the EGR valve does not
open, engine detonation occurs. When a defect occurs in the EGR system,
a diagnostic trouble code (DTC) is usually set in the powertrain
control module (PCM) memory.
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Typical computer-controlled EGR system. Reprinted with permission of Ford Motor Company.
In many EGR systems, the PCM uses imputs from the engine coolant
temperature (ECT) sensor, throttle position sensor (TPS), and manifold
absolute pressure (MAP) sensors to operate the EGR valve. Improper EGR
operation may be caused by a defect in one of these sensors. A scan
tester may be connected to the data link connector (DLC) to check for
an EGR DTC or a DTC from another sensor which may affect EGR operation.
The cause of any DTCs should be corrected before any further EGR
diagnosis.
HOW TO TEST EGR VALVE
Cont....
Thanks for your response!!
EGR VALVE REMOVAL/INSTALLATION Disconnect the negative battery cable
Remove in the order indicated below.
EGR valve connector
EGR valve
Install in the reverse order of removal.
Connect the negative battery cable.
Let me know, if needed further assistance.
Hope i helped you.
Thanks for using ' Fixya ' and have a nice day!!
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It's easy. Remove the intake duct from the air cleaner to the engine. Push down on the back tab on the electrical connector then pull gently to remove it. Set intake duct aside. Remove electrical connector from EGR the same way. Remove the two EGR bolts with 12mm socket. When you remove both bolts the EGR valve gasket will fall to the ground unless you can catch it. Remove valve.
To replace install the two bolts and gasket and hold bolt heads in place while you wiggle valve into position. Reinstall everything and you're done
NOTEDigital EGR Valve Diagnosis
The digital EGR valve may be diagnosed with a scan tester. With theengine at normal operating temperature and the ignition switch off,connect the scan tester to the data link connector (DLC). Start theengine and allow the engine to operate at idle speed. Select EGRcontrol on the scan tester, and then energize EGR solenoid number onewith the scan tester. When this action is taken, the engine rpm shoulddecrease slightly. The engine rpm should drop slightly as each EGRsolenoid is energized with the scan tester. When the EGR valve does notoperate properly, check these items before replacing the EGR valve:
Digital EGR valve circuit. Courtesy of Oldsmobile Motor Division-GMC.
Linear EGR Valve Diagnosis
The linear EGR valve diagnosis procedure varies depending on thevehicle make and model year. Always follow the recommended procedure inthe vehicle manufacturer's service manual. The scan tester may be usedto diagnosis a linear EGR valve. The engine should be at normaloperating temperature prior to EGR valve diagnosis. Since the linearEGR valve has an EVP sensor, the actual pintle position may be checkedon the scan tester. The pintle position should not exceed 3% at idlespeed. The scan tester may be operated to command a specific pintleposition, such as 75%, and this commanded position should be achievedwithin two seconds. With the engine idling, select various pintlepositions and check the actual pintle position. The pintle positionshould always be within 10% of the commanded position. When the linearEGR valve does not operate properly:
Linear EGR valve circuit. Courtesy of Chevrolet Motor Division-GMC.If the EGR valve did not operate properly on the scan tester and tests 1 through 5 are satisfactory, replace the valve.
I own a 2002 Mazda Protege5 with the FS2.0 Motor. The EGR Valve is located below the throttle-body. You must take off the Intake tube to get a good view of it. To replace it I think you might have to take off the throttle-body, but I'm not sure about that...(yet)
NOTE: Mazda put out a technical note stating that "if your car has sat for a long time, the egr valve could be damaged by moisture (rain) and will need to be replaced". My 2002 Protege sat for 3 weeks and the rain caused this exact issue and had to be replaced. How did I know? The engine light came on (after never coming on) and the car had an extremely rough idle. Total cost was ~$400 (ouch).
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