I have an engine code P0404 showing up on my 2002 Monte Carlo. I replaced the EGR valve but this did not fix the issue. Please help! I am getting almost no power under load. Very slow accelaration.
There are a myriad of things that can cause a "Exhaust Gas Recirculation Circuit Range/Performance" fault. I think you best bet would be to have it checked by a pro, it'll save you from replacing parts that don't need replacing. Good luck.