Just bought an 05 MC last week. My SES light has already came on twice! First time was a small EVAP leak (assumed it could be the gas cap) and the pre-cat O2 sensor. I replaced the sensor and the light went out. It came back on today with three codes: both O2 sensors AND EVAP leak. Could my engine be running lean? What might be some other solutions? The car seems to drive and perform just fine.