2002 Mazda Millenia V6-2497 2.5L P0421 bank-1 and P0431 bank-2 and P1521

Question

I am asking how I can fix my Car Mazda, 2002 Millenia , a reading of P0421 bank-1 and P0431 bank-2 and P1521, I just replace the Catalytic Convertor last weekend how much am I looking at Price wise can I do this myself, please HELP!!!

Answer 1

P1521 VRIS solenoid valve No.1 circiut malfunction

This code usually set a lean bank code on both side of the Bank, for now check the vacuum hose routing and its connection replace if any is ruptured . and a VRIS solenoid  on number make sure it is connected , you may have to replace the VRIS for No.1