Error code P0404 what is the EGR Valve?

The P0404 code error comes when the EGR doesn't behave as it should Most of the time, it's because the valve doesn't open Besides the valve

Detailed information on troubleshooting and repairing a p0404 automotive trouble code which refers to an EGR circuit range or performance issue

p0404 Code P0404 usually indicates that there is a carbon build-up somewhere in the lines, or on other occasions, a bad EGR valve

p0404 I bought a Puma unlock code for my Nanocom and plugged it in yesterday and I am getting the fault code CODE: P0404 Exhaust gas