Engine Code P0404 - Tuning & Modifications

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?

2 years ago, a a month after I bought my i30 , I had a CEL with a P0404 code that was set while on a long road trip in

code p404 P0404 Exhaust Gas Recirculation Circuit RangePerformance EGR Valve

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