EGR THERMO Valve
- With engine at operating temperature and idling, disconnect the vacuum sensing tube from the EGR valve. Apply manifold vacuum to the EGR valve. The engine should run roughly or stop.
- If the engine does not respond as described, disconnect the EGR control valve-to-EGR thermo valve pipe. With engine running, check to see if a flow of exhaust gas is present. If not, EGR thermo valve is defective and must be replaced.