Now what!!! Check engine light and Trac lights on.. tried the gas cap.. nope!

What is your question?

Has anyone found a mess on the engine after oil change.. was told that the filter had to be changed from the top?? Reset the CEL.. and after 90 miles.. just about exactly .. it came back on.. How does one know really.. after many codes.. if it's #1 or #2 oxygen sensor... yes I will get the codes.. but this all seems so redundant.. too many people with the same problem.. single older female.. I am a walking target!