Pesky P0404 code 99 Silverado

code p0404  P0404 fault code This code refers to the EGR valve and its performance On the code reader it refers to 'A'control circuit Does anybody know 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?

The error code P0404 can be defined as Exhaust Gas Recirculation Circuit RangePerformance  Failure code of P0404 had been recorded I removed the EGR valve and discovered that small pieces of carbon had logded the valve open

Monte Carlo Repair Help - P0404 engine code 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