P0400 - Exhaust Gas Recirculation Flow Malfunction

[Kigiin]

Popped a CEL with this code shortly after adding an aux fuel tank. I replaced with a gently used charcoal canister and all was fine.

Two years later now, I am getting this same code as a pending trouble code, but never actually throws a CEL. It has done this twice now, always just pending, never throwing a CEL, and then going away.

Thoughts?

 

[Kigiin]

No one?

 

[Trunk Monkey]

Sounds like your aux tanking is hosing up your charcoal canisters.

 

[Kigiin]

Yes, but why do you think... too fumey?

 

[OregonLC]

How does EGR and EVAP correlate? I can see fuel issues affecting EVAP codes, but the exhaust side seems way disconnected from that loop.