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96 Camry did not pass DEQ inspection

In our city our cars need to pass a “DEQ Inspection” prior to renewing our tags. The diagnostic came back saying that detected an “insufficient flow of exhaust gas recirculation”.

I asked the tech what this meant? He said that the EGR might be plugged or they need to be replaced/



Can I unplug myself or replace it myself?

Do you have the L4 or the V6 engine in this Camary? Was there a specific Diagnostic Trouble Code recorded and can you include that in your posting?

Usually when the EGR DTC codes sets for insufficient flow, it could be anything from a broken vacuum line to a plugged passage. The PCM is just letting it be known that it did not see the correct engine response to a commanded EGR action. It doesn’t know or care where the exact problem is located. Ergo, follow the troubleshooting tree for the DTC code recovered.

There are a number of things you will have to check. For the L4, there is the EGR valve itself; the exhaust gas pipe; the EGR back pressure transducer; the EGR solenoid; and the EGR vacuum regulator solenoid. There are similar units to check on the V6. The EGR valve will be harder to access on the V6.

Good luck on this.

V6. P0401
Is there a way to unplug the passage or at least to check if there is a plugged passage?

Thanks!

Yes. Remove the EGR, and run a fine wire down the passages in the manifold. Sometimes the riser pipe, if so equipped, can get plugged, and replacing it is easier than chipping the carbon out of it.

Thanks! Let’s give her a try!

Another way to check without removing the EGR valve is to apply a vacuum supply to the EGR diaphragm. If the engine stumbles badly and/or dies you know that there is sufficient flow available.

BTW the PCM senses the gas flow in the V6 with a temperature sensor built into the EGR valve. Interesting feed back method.