Contour Enthusiasts Group Archives Forums General Troubleshooting P0402 EGR Flow exsessive at idle?? how to fix

A quick easy test for the EGR Vacuum regultor is this...

Remove the Vacuum hose from the EGR Valve.
Place a Vacuum gauge or vacuum pump on the end of the hose,
in place of the egr valve.
At Idle, the vacuum should be ZERO.
If the vacuum is anything other than zero,
the regulator is leaking,
and the leaking vacuum is opening the EGR valve,
and throwing the code you got.

No need to replace the EGR Valve unless the Vacuum
reading stays at DEAD ZERO.

Don't clean it - REPLACE IT.