P1131 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1.


seems that you might need a new O2 sensor but that shouldn't have anything to do with the engine idle

I would check the IAC to start

- 95 Mystique LS - Zetec/5spd - 99 Contour SeVT Sport - Duratec/5spd Official NE-CEG Contour/Mustang Family