96 Camry did not pass DEQ inspection

toyota
camry

#1

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?


#2

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.


#3

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

Thanks!


#4

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.


#5

Thanks! Let’s give her a try!


#6

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.