D40 P0403 Fault Code Persists after EGR Valve Replacement

[JimmyC]

G'day,

I've been having ongoing issues with my D40's EGR System.

I replaced the EGR vale in early 2022. 18 months later I was having power/boost issues so replaced the boost control solenoid with a tillix system. It came with an EGR blanking plate, so I fitted that too.

About 1000 km's later it started throwing P0409 codes. Tried removing the blanking plate, no change. Took the valve off, could see that it wasn't closing properly, gave it a clean and put it back. No change. Replaced the valve with a new one and refitted the blanking plate. Still throwing codes. Took it to my local mechanic, they checked it with an oscilloscope and reset the valve position manually. It's now showing a P0403 code. Removed the blanking plate, code still there.

What's also odd is every time I delete the code, it doesn't reappear immediately. It always waits at least two stop/start cycles before the code reappears.

I've got no idea what to do next. Any ideas?

Thanks in advance.

 

[australianoz]

Hi Jimmy, what year model are we talking about here? If it's a Euro 5 (aka 2015 and above) you need a resistor in series with then intake temp sensor of the MAF.

 

[Andy.ob]

When i blanked my egr on my V9X i had to have the codes removed from the ECU also by a autoelec as even though it is blanked off, the sensor part is still working and will record issues now that it is blanked.
Also if you go the same route as me, dont drill a 10mm hole in the plate as it would not be required and is only a temp fix if you did not get the autoelec to turn off the codes.