Front O2 sensor replaced less than 1k miles ago. It was throwing codes for that. No more codes, and running condition improved after the change.
Mine: 2002 Focus SVT: 142k, Sonic Blue, #1654, All Options
Mods: Tom's Tune, Borla, HFC, STS, Painted Machs, Euro Grill, FRPP Springs
Hers: 2010 Focus SES: 67k, Ebony, Auto, Moon and Tune