cold O2 sensor output question
12-04-2013, 11:23 PM
#1
cold O2 sensor output question if an o2 sensor is cold, or say the exhaust system has cooled off and you restart the vehicle, and immediately read the o2 sensor without turning on it's heater how would it read? what voltage was it output, low meaning lean or high meaning rich?
for the catalytic converter, if that is cold and not doing it's thing then the exhaust gas leaving the cat would be low in oxygen or high in oxygen?
for the catalytic converter, if that is cold and not doing it's thing then the exhaust gas leaving the cat would be low in oxygen or high in oxygen?
12-05-2013, 12:30 PM
#2
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The output will be low until the sensor gets warm
enough to work chemically. Then it will follow what's
in the pipe, which may be a mystery. Unless the PCM
has faulted the sensor, in which case it will jam it
to 450mV or so.
If the gas is cold then the cat will not modify it. The
cat needs to "light off" and this is why the AIR system
is there. But AIR operation will jack the readings way
lean while it's running.
enough to work chemically. Then it will follow what's
in the pipe, which may be a mystery. Unless the PCM
has faulted the sensor, in which case it will jam it
to 450mV or so.
If the gas is cold then the cat will not modify it. The
cat needs to "light off" and this is why the AIR system
is there. But AIR operation will jack the readings way
lean while it's running.