DS4 2.0 blue hdi faulty deNOx system

[wheeler]

Strange thing is the system showed working again when the fault codes were deleted without doing anything else.

I would kind of expect that, but if/when it sees the fault again it would just come back on.

[Hell Razor5543]

What can happen is that when an error is cleared (and the faulty part is replaced) the ECUs wait for a certain number of engine cycles (normally five times) before accepting the problem HAS been resolved.