code p0133 for 1999 grand am

What is your question?

Engine idle fluctuates while stopped at light or in slow traffic. Hard to start sometimes after stopping at the store. Engine still warm. Starts good when engine is cold. Can smell gas shortly after starting when cold. Service Engine Soon light comes on - scanner code is P0133. Have changed the gas cap.

What makes this problem better or worse?

It's worse when engine is hot/warm

How long has your 1999 Pontiac Grand Am had this problem?

more than once over the last year