1. The EGR system is usually located on the intake manifold (carburetor) or throttle body (injection). The biggest problems in the EGR system are bypass valve sticking and corrosion.
2. On a cold engine, press the diaphragm of the EGR valve actuator: applying and relieving pressure (finger of the hand) you should feel the valve move.
3. If there is no movement or it is with great effort, replace the valve.
4. Detailed information is set out in Chapter 6.