My MIL light keeps coming on with DTC code P0401. "Insufficient flow detected in EGR system." I've replaced the EGR valve. But about 2 weeks later, same error "P0401." Now I can't even drive around the block after resetting the MIL without it coming on again. I've inspected the EGR valve and manifold port and didn't see any deposits other than a slight black dust.

Anyone have any suggestions? Thanks.

 

UPDATE: I just cleaned the intake port AND the EGR valve with carberator cleaner as instructed in the service manual for DTC P0401. I just about emptied the can in the ports. Reset the MIL...started the engine...drove it...still gives me DTC P0401. I've replaced the valve but only got about 2 weeks without the error code showing. Please, can someone offer me any help with this? EGR valves are expensive, and I don't want to buy another one...This is getting very frustrating...

 

The EGR system has more components that just the valve, I suggest you buy a Helms.