[compnut21]

.... except for the fact egr is closed at idle.

Originally Posted by magik8

Dyoel is correct, EGR (Exhaust Gas Recirculation) is the process of the ECU introducing a portion of the exhaust gas into the intake manifold which reduces combustion temperature and NOx (emissions). (Mazda MX6/626 Training Manual, 1988)

On the nonturbo engine, EGR is only cutoff under the following conditions:

1) Sudden accelleration or deceleration
2) Radiator coolant below 63 F AND Engine coolant below 158 F
3) Engine speed below 1500 rpm

On the turbo engine, EGR is controlled as follows (Mazda MX6/626 Training manual, 1988)

1) Throttle plate fully closed or "above apecified opening angles, changes due to engine speed" - Cut off
2) Sudden Accelleration - reduced to one half
3) Sudden Deceleration - Cutoff
4) Radiator coolant below 63F and Engine coolant below 104F - Cutoff
5) Engine coolant between 104 F and 122 F - Reduced