Error code P0400

[pete1975]

Toyota Rav 2.2 d4d 2008

started getting check engine system ,check 4x4 and check VCR system

plugged in diagnostic tool and got error code P0400. had EGR valve cleaned and manifold clean as much as it could be. even had a new EGR valve fitted which made no difference. the problem was still there.

none of the cleaning had any effect , I've been told it could possibly be a issue with a turbo booster pipe leaking as I'm getting a slight loss of power when pulling away. which then clears and runs fine.

taken error codes off but after a short while there back.

on start up the check engine system light stays on.

Any advice would be great fully received.

[Devon Aygo]

There is more to the EGR system than just the EGR valve & manifold and if you have cleaned these and are sure they are functioning then you will need to check further back in the EGR circuit.

The engine ECU is detecting insufficient air flow through the EGR system attached is a pic of the EGR routing:

Green is the route of the exhaust gas from the exhaust through EGR Cooler onto the first EGR Valve then through the side if the cylinder head and onto the main EGR valve before entering the intake manifold there could be a blockage of carbon or either of the valves could be stuck/sticking shut. 

There aren't any EGR blanking plates fitted?

Note: this is a pic from a later AD engine so the Yellow EGR is a different shape & you most likely don't have the Purple one but the routing is correct and you will definitely have the blue EGR cooler