The AC Expansion Valve may develop a very slow leak or allow too much refrigerant flow which reduces cooling. Our technicians tell us that Toyota makes an updated expansion valve to resolve these problems if and when they occur.

Over the time the exhaust gas recirculation (EGR) system may become plugged with debris, the oxygen sensor may also be getting slow or 'lazy' around this time. When servicing or cleaning the EGR system, it is a good idea to replace the oxygen sensor because it works in tandem with the EGR system.