Camry 2.2L 4-Cyl., Celica, RAV4, Supra Turbo, Tacoma 2.4L 4-Cyl. & 2.7L 4-Cyl., Tacoma 3.4L V6 2WD All Models & 4WD Regular Cab, T100 2.7L 4-Cyl., T100 3.4L V6 2WD 1/2 Ton & 4Runner 2.7L 4-Cyl.

The EGR system reduces oxides of nitrogen (NOx) emissions by lowering combustion temperatures. Combustion temperatures are lowered by recycling metered amount of exhaust gases back into the intake system. The EGR system contains a vacuum-operated EGR valve, EGR vacuum modulator and EGR Vacuum Switching Valve (VSV). See Figure-38. EGR vacuum modulator regulates exhaust backpressure and balances atmospheric pressure and vacuum to allow EGR operation at heavy throttle. The EGR valve operation is controlled by EGR VSV which is controlled by the Engine Control Module (ECM).

On Tacoma, T100 and 4Runner, EGR gas temperature sensor is used in the EGR system. On all models, ECM uses various input signals for controlling EGR system operation. For EGR system and component testing, see SYSTEM/COMPONENT TESTS article.