I have a 2001 Impala with these two Error Codes -- P1404-EGR & P0440-Evap. I replaced the EGR for $100, replaced the gas cap and cleared the errors. They came back. I am losin it! Anyone know what might be causing these error codes or where to look for the evap problem?

2001 Impala-Error Codes P1404-EGR & P0440-Evap
I have replaced the EGR and the gas cap. I cannot erase the codes. Anyone know what I can do to correct these emission errors? Where to look? Anything??

take your vehicle to your local auto zone and ask them to hook up the scaner and erase the codes

There is an emissions box above and behind the left rear wheel (driver) that is prone to cracking and leaks. If this happens it will set those codes. We found it by hooking up a smoke machine to the vacuum system and watching for smoke. VOILA it was leaking from the back end, replaced the piece $65 part and no more trouble