EGR Valve Test

[cyoung59]

CEL came on code P0401. Did the usual egr flow cleanout. CEL popped again different code pointing to EGR valve sensor or mechanical failure.

My Haynes manual gives instructions for testing continuity of the sensor 6 pin connector. Says should be continuty between pin 1&2 and 1&3 if not replace EGR. (Mine showed high resistence/no continuty). Mechanical test jumps positive battery terminal to 4 pin negative to six pin. Engine should run rough or stall. If not replace EGR. (There was no change in mine).

I replaced the EGR (under warranty) but still popped the CEL and got same test results. Tested a couple other new EGRs at Auto Zone for continuity and all failed.

1. Is my Haynes manual instruction incorrect?
2. Does Auto Zone have an *ss load of bad EGRs?
3. Am I doing something wrong?

Any help would be appreciated. Especially EGR test instructions from an actual '98 Honda service manual.

Thanks much.
Chuck

 

[jwong512]

Did you open the intake manifold and clean the top part of the hole? Cause cleaning the actual EGR valve itself won't do much since it's the actual passageway that gets clogged. I would remove the intake manifold, clean out the top and bottom grooves where the EGR is supposed to flow. Then take the EGR out and clean out the passageway under there. Gotta clean both ends really nicely for it to flow smoothly.

 

[cyoung59]

Yes. The EGR passage has been thoroughly cleaned on the intake manifold and the engine block side. Now I'm wondering if I'm getting voltage to the EGR sensor through the connector. Still wondering about the EGR test instructions in the Haynes manual though.

cy

 

[xi0utlawstarix]

could be a clog somewhere in the egr system.

I got p0401 code from this

 

[cyoung59]

Thanks xiOutlawstrix. That's a healthy clog! What component did you remove to reveal that?

cy

 

[nine23]

Thanks xiOutlawstrix. That's a healthy clog! What component did you remove to reveal that?

cy

Sorry for bumping an old thread but I am wondering the same

 

[CanadianEh48]

Not to thread jack, but im about to do clean the EGR passage, and Im thinking of just deleting it all together.

Where can I purchase a blocker plate?