I replaced both O2 sensors with the new cat converter... the P0172 code cleared itself before I got to Orily's so im guessing there was just excess fuel in the system because of the faulty cat and stuff... I also bought a new gas cap so we'll see if that code pops back up after I drive it around a bitThat hasn't cleared codes since at least '96 model year. You'll need a scan tool or code-reader to clear the codes.
Evap system is often a failed (or loose) gas cap. Can be lots of other stuff, but often the cap.
How old are the O2 sensors?