I got this message, "Check Engine Oil". I checked the dip stick and I have oil. on 2003 Chevrolet Impala

Oil change was done about 1 month ago and I took your advice previously about the cat. converter and I had that replaced.

Asked by for the 2003 Chevrolet Impala
Every time you change your oil you need to go into your cars computer and reset the oil life option. This is done through your radio. The details on how to do it are in your owners manual. If you don't have one I can maybe help you further.
2 answers
It could be a faulty low oil level switch.