Not necessarily. The sensor is not grounded, it is simply
malfunctioning. It isn't doing anything that would cause a 21 (sensor
voltage shorted to ground, input voltage above normal range, neither
rich nor lean condition detected, or heating element malfunction). The
sensor seems to be constantly sending a lean condition signal (low
voltage, around 120mV) to the PCM, so all the PCM sees is a constant
lean condition and dumps fuel to richen the mixture.
Bob Tom wrote:
>
> At 08:05 PM 3/23/04, you wrote:
>
>> I checked the O2 sensor today (per Chilton's) and it's only
>> putting out about 120mV regardless of engine speed or how
>> long it's run. So, according to Chilton's, the PCM is interpreting
>> that as a lean condition and dumping more fuel to compensate.
>> I'll replace it tomorrow and see if it fixes it
>
>
> If that's is the case, I would have thought that a code 21 would
> have been generated.
>
> Bob
>
This archive was generated by hypermail 2b29 : Sat Feb 16 2008 - 21:39:22 EST