Hi,
P0401 code...
I have cleaned vacuum lines and EGR valve ports.
Code back @ 60 miles and 92 miles second time, CEL was reset each time.
Before I throw a new EGR valve in (which seems to be working as it should, it is seated and moves when vacuum source is applied) does the solenoid valve throw this code also or does it have its own. I have vacuum up to the solenoid valve but have not noticed any vacuum at EGR and the line is clear. When is the solenoid valve supposes to operate and does it use 12v.

Thanks, Tom
97 Accord 180k
87 CRX 152k

 

The solenoid could be the problem. Does the vacuum line to the egr valve show vacuum when you raise the rpms to about 1500-2000? If not, does the ecu energize the egr solenoid under the same conditions? (the engine needs to be warmed up to)

 

a 401 code will most likely be the egr ports clogged,look under youf fuel rail and you will see a plate,take it off and clean the clogged ports out.