Quote:
Originally Posted by leefpile  I have a p0401 code and I am losing my mind over this. I replaced the DPFE a few months ago when I first got the code. It came back now. I replaced the VAC control solenoid. |
The most common cause of a P0401 is a clogged passageway. Either from the exhaust manifold up to the the EGR valve or from the EGR valve to the intake manifold.
Quote:
|
The EGR valve moves what I think is properly with vacuum applied.
|
Good visual check ! If you apply a vacuum to the EGR valve while the engine is at idle it should stumble badly or stall. If not, one of the passageways I mentioned is clogged.
