Exhaust Gas Recirculation: Testing and Inspection

1. INSPECT AND CLEAN FILTER IN EGR VACUUM MODULATOR
- Remove the cap and filter.
- Check the filter for contamination or damage.
- Using compressed air, clean the filter
- Reinstall the filter and cap.

HINT: Install the filter with the coarser surface facing the atmospheric side (outward).





2. INSTALL VACUUM GAUGE
- Using a 3-way connector, connect a vacuum gauge to the hose between the EGR valve and EGR vacuum modulator.
3. INSPECT SEATING OF EGR VALVE
- Start the engine and check that the engine starts and runs at idle.





4. CONNECT TOYOTA HAND-HELD TESTER OR OBD II SCAN TOOL
- Connect the TOYOTA hand-held tester or OBD II scan tool to the DLC3.

Please refer to the TOYOTA hand-held tester or OBD II scan tool operators manual for further details.

5. INSPECT VSV OPERATION WITH COLD ENGINE
- The engine coolant temperature should be below 50°C (122°F).
- Check that the vacuum gauge indicates zero at 3,000 rpm.
- Check that the EGR pipe is not hot.
6. INSPECT OPERATION OF VSV AND EGR VACUUM MODULATOR
- Select the active test mode on the TOYOTA hand-held tester (VSV is closed.).





- If you have no TOYOTA hand-held tester, check these procedures:
(1) Remove the 3-way connector with the vacuum hose.
(2) Connect the vacuum hose (from port Q of EGR vacuum modulator) to the EGR valve.
(3) Plug the vacuum hose (from VSV for EGR).
- Check that the vacuum gauge indicates low vacuum at 3,000 rpm.
7. DISCONNECT TOYOTA HAND-HELD TESTER OR OBD II SCAN TOOL
8. REMOVE VACUUM GAUGE
- Remove the vacuum gauge, and reconnect the vacuum hoses to the proper locations.





9. INSPECT EGR VALVE
- Apply vacuum directly to the EGR valve with the engine idling.
- Check that the engine runs rough or dies.
- Reconnect the vacuum hoses to the proper locations.
IF NO PROBLEM IS FOUND WITH THIS INSPECTION SYSTEM IS NORMAL; OTHERWISE INSPECT EACH PART





10. REMOVE EGR PIPE
- Remove the bolt, 4 nuts, EGR pipe and 2 gaskets.

INSTALLATION HINT: Install 2 new gaskets.

Torque:
Bolt: 18 N.m (185 kgf.cm, 13 ft.lbf)
Nut A: 19 N.m (195 kgf.cm, 14 ft.lbf)
Nut B: 20 N.m (200 kgf.cm, 15 ft.lbf)





11. REMOVE EGR VALVE
- Disconnect these hoses:
(1) Vacuum hose
(2) EGR hose
(3) Water bypass hose (from IAC valve)
(4) Water bypass hose (from water bypass pipe)
- Remove the 2 nuts, EGR valve and gasket.

Torque: 19 N.m (195 kgf.cm, 14 ft.lbf)





12. INSPECT EGR VALVE
- Check for sticking and heavy carbon deposits.
- If a problem is found, replace the EGR valve.





13. DISCONNECT VACUUM HOSES FROM EGR VACUUM MODULATOR
14. INSPECT EGR VACUUM MODULATOR OPERATION
- Block ports P and R with your finger.
- Blow air into port Q, and check that the air passes through to the air filter side freely.





- Start the engine, and maintain speed at 3,000 rpm.
- Repeat the above test. Check that there is a strong resistance to air flow.
- If operation is not as specified, replace the EGR vacuum modulator.
15. RECONNECT VACUUM HOSES TO EGR VACUUM MODULATOR





16. REMOVE CHECK VALVE
17. INSPECT CHECK VALVE
- Check that air flows from the orange pipe to the black pipe.
- Check that air does not flow from the black pipe to the orange pipe.
- If operation is not as specified, replace the check valve.
18. REINSTALL CHECK VALVE

HINT: Reinstall the check valve with the orange pipe facing the EGR vacuum modulator side.

19. VSV FOR EGR INSPECTION