Hesitation and hard start on start up

[SPLLOUDER]

The 01 Bonneville SLE has begun to have some ruff starts. "Sometimes worse when it is cold outside " It turns over great but spudders and just does want to fire up unless you press the gas pedal slighty it will fire up everytime right away . Any ideas ?

P.s. Also the SES light is on and think it said something about egr and o2 sensors .

[96 SSEi]

Hi, you can try to pull the ses codes and get the proper number so you can trace the issue properly- once you get the codes, someone will help you