First the right meanings for the codes are.....
(332)Insufficient EGR flow detected(EGRP,EVP,PFE,DPFE)
(551) IDLE air Control (IAC) cicuit failure KOEO
Second for code 332 check and see if the egr holds vaccum, if it does mostly likely its your DPFE sensor
For code 551 mostly like you will need to replace your IAC sensor. Good luck and hope that helps
