I have a code P0401,cleaned passage system, (no luck), replaced egr,(no luck) on 1997 Toyota Corolla

I'm in the process of finding a book with drawings that tells me more about my problem. I need help!!!

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1 answer
for p0401
Possible Solutions:
In fixing this code, it is quite common for people to just replace the EGR valve only to have the OBD code return. The EGR valve is not always the culprit.
Use a vacuum pump and pull the EGR valve open while monitoring engine RPM's & DPFE voltage. There should be a noticable difference in RPM's with the EGR open
Clean out the EGR valve and/or tubing to remove deposits
Check the voltage at the DPFE, compare to specified values (refer to a repair manual for your specific model)
Replace the DPFE sensor (with a good quality / OEM one)
Replace the EGR valve