Guys,

P0401 Exhaust Gas Recirculation Flow Insufficient Detected,
I took the EGR valve off, cleaned it with carb. cleaner, got deep down inside it with a battery cable brush (male end) which works GREAT, btw.

What else could cause this code?

Thanks!

(Posting same question in Exhaust section.)

 

DPFE sensor. I had that code around 40K miles and replaced the DPFE. No more codes.

 

Either clogged EGR ports or a faulty DPFE sensor, most likely.

Do a SEARCH for "P0401". Very frequently a topic of discussion.

Perform the "suck test" to isolate between clogged ports or sensor.

Steve

 

Apply vacuum to the EGR valve with the engine at idle and see if it stumbles. If not, then most likely the ports are clogged, not allowing EGR flow into the engine. Or the EGR valve is stuck closed, but more than likely it's the ports.

 

What and where is the DPFE sensor?