Hi, 

 

So my car is an old 2004 1.9 tdi Octavia, 180k miles on the clock.

The engine light came on and I read the code - PO401 - EGR flow insufficient detected.

I cleared the code/light but it came on again about a mile later. This was from a cold start. When the engine was up to temp, I cleared it again and the light/code did not reaper (I drove about 100 miles which may or may not have been the thing to do!). But still no light.

The next day it did the same. So it seems it's getting the fault when cold, but when warm everything is OK.

 

Any ideas what I should look at first? All I've tried so far is a can of the EGR cleaner you spray up the air intake pipe.

 

Thanks for any help!

 

Alan

Is that the BKC engine with the ASV and then EGR bolted to the manifold? Check all vacuum pipes for any deteriorating. The valve that controls the egr can sometimes go faulty. Also the maf sensor measures the air into the engine which could report wrong and cause the same fault. You can try taking off the egr and cleaning it if it's a bit sticky. After that it will be new one.

1 hour ago, Blue8793841 said:

Is that the BKC engine with the ASV and then EGR bolted to the manifold? Check all vacuum pipes for any deteriorating. The valve that controls the egr can sometimes go faulty. Also the maf sensor measures the air into the engine which could report wrong and cause the same fault. You can try taking off the egr and cleaning it if it's a bit sticky. After that it will be new one.

Hi, thanks. It's either an ALH or AGR engine. The EGR sits at the top at the back 

I'll check those pipes, seems a sensible place to start. The EGR itself was replaced a few years ago, but maybe an old diesel engine clogs it up quickly!