Injuneer

It would help if you just provided the actual code. Look through this list, and find one that says "left o2 lean"......

P0131 Heated Oxygen Sensor (HO2S) circuit low voltage Bank 1 Sensor 1
P0132 Heated Oxygen Sensor (HO2S) circuit high voltage Bank 1 Sensor 1
P0133 Heated Oxygen Sensor (HO2S) slow response Bank 1 Sensor 1
P0134 Heated Oxygen Sensor (HO2S) insufficient signal activity Bank 1 Sensor 1
P0135 Heated Oxygen Sensor (HO2S) heater circuit Bank 1 Sensor 1
P0137 Heated Oxygen Sensor (HO2S) circuit low voltage Bank 1 Sensor 2
P0138 Heated Oxygen Sensor (HO2S) circuit high voltage Bank 1 Sensor 2
P0140 Heated Oxygen Sensor (HO2S) insufficient signal activity Bank 1 Sensor 2
P0141 Heated Oxygen Sensor (HO2S) heater circuit Bank 1 Sensor 2

P0171 Fuel trim system lean Bank 1
P0172 Fuel trim system rich Bank 1

Do you mean P0131, indicating "low voltage" on the driver's side pre-cat, which would indicate a stationary signal less than 200mV? Or was it possibly P0171 fuel trim "lean"?

blackz151

it reads a low voltage when it goes bad. like it keeps jummping around