I've had the P1283 code for some time now, and finally decided to replace the O2 sensor. Well that didn't work. Code is back. It use to only come on when it was cold out, and be fine in the summer, but now its on all the time.

Could it be an exhaust leak? Whats the best way to find an exhaust leak? P1283 is for a lean condition, however I can smell gas when I give it throttle.