4 Runner 2WD L4-2693cc 2.7L DOHC MFI (1997)
Vacuum Check Valve: Testing and Inspection
EGR Vacuum Check Valve Inspection
1. Remove check valve.
2. Inspect check valve.
(a) Check that air flows from the orange pipe to the black pipe.
(b) Check that air does not flow from the black pipe to the orange pipe.
If operation is not as specified, replace the check valve.
3. Reinstall check valve.
HINT: Reinstall the check valve with the orange pipe facing the EGR vacuum modulator side.