I have a 07 skoda octavia 1.9 tdi, engine management light came on .

the code showing was p0401 egr insufficient flow (intermittent ) , took off egr valve and cleaned out , the egr valve wasn't that bad.

code was reset ,

Today engine management light came back . valve was working fine when attached to a vacuum pipe.

has anyone any ideas what the problem could be.

i am doing about 100 to 150 miles day so i don't think it's short journeys causing it.

any help much appreciated .

Assuming the EGR vacuum control is OK, it will be either a faulty EGR valve or leaking gasket. The EGR can look OK but still stick.

Hi,

replaced egr valve, cleared code engine light came back on same fault (P0401 Exhaust Gas Recirc.Flow Insufficient Detected).

has anybody any ideas what it could be that's causing the code to come up. The engine seems to be running fine so i don't think its the vacuum control module.

Vacuum control module.

Thanks for your reply , i did think about the vacuum control module but it has about 6 pipes coming off it .

so i thought if it was faulty it would cause other problems with the engine, but its not car is running fine.

Could it be a software problem.

Do you know what a new module would cost

I had the P0401 fault code on my 1.9tdi SEAT Leon.(Same VW engine as Skoda) I cleared the code a number of times and it would be OK for a few days then pop back up. I eventualy took the sound proofing engine cover off and checked the vacuum pipes in the area of the EGR valve. I found that one of these had rubbed against the inlet manifold and worn through. I think that the INSUFFICIENT FLOW refers to flow through the associated valves and sensors rather than the EGR system itself. There do not appear to be any sensors on the EGR valve or pipework.