Exhaust gas recirc flow prob P0400?

[NPS]

This error came up when really hot in standing traffic today.

P0400 - Exhaust Gas Recirculation Flow Malfunction

Car is 3.0 V6 diesel 2005

This sounds like something related to EGR valve?

Thanks
N

[lee gsi]

On my 1.9 CDTi that code was EGR related.

cleaned it and all is wel.

[hebblemarine]

The ECU looks at the fresh air flow in (MAF sensor) and the boost pressure (manifold pressure) and temperature. From this it can work out the amount of exhaust gas recirculation taking place. If it's not within some set limit, then a code is thrown (this happens whan the EGR is blanked). If the valve is faulty / dirty / sticking, then that situation could arise.

Could be worth taking it off for a clean as lee gsi suggested. Else it could be kaput. EGR function can be checked on tech2 etc if you don't want to get your hands dirty.