P0404 code

code p0404  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 The code may be thrown due to a clogged cat with too much back pressure anyone here ever encounter that or have any other thoughts?

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 Causes and Fixes P0404 Code: Exhaust Gas Recirculation Control Circuit RangePerformance

i replaced egr at first it worked fine for a while until car started giving the code p0404 again and the engine went into safe mode Tester Monte Carlo Repair Help - P0404 engine code