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- Jun 2, 2012
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- canada
- Vehicle Year
- 1994
- Make / Model
- Ford
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- Manual
O2 has the biggest "say" in the air:fuel department, as far as sensors, computers interpretation of the sensor data is of course the ultimate control.
MAP sensor allows computer to set baseline 14:1 air:fuel
After cylinders burn this mix, O2 sensors report lean/rich oxygen levels
Computer adjusts mix ratio, fine tunes, for best MPG
Computer changes mix slightly a few times a second to hover around the O2 sensors "sweet spot", .4-.5volts
This switching allows computer to test if O2 sensor is responding fast to changing mixes and also responding correctly to lean or rich.
Computer has pre-set parameters for engine size and injectors dwell time, if injectors are being opened to long to achieve .4v O2 response then computer will set a Lean code, engine isn't running lean the code is set because there is a problem with the system, could be a vacuum leak, more air than calculated or low fuel pressure, so longer injector open time needed.
MAP sensor allows computer to set baseline 14:1 air:fuel
After cylinders burn this mix, O2 sensors report lean/rich oxygen levels
Computer adjusts mix ratio, fine tunes, for best MPG
Computer changes mix slightly a few times a second to hover around the O2 sensors "sweet spot", .4-.5volts
This switching allows computer to test if O2 sensor is responding fast to changing mixes and also responding correctly to lean or rich.
Computer has pre-set parameters for engine size and injectors dwell time, if injectors are being opened to long to achieve .4v O2 response then computer will set a Lean code, engine isn't running lean the code is set because there is a problem with the system, could be a vacuum leak, more air than calculated or low fuel pressure, so longer injector open time needed.
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