PH98I30

Does this code mean the O2 sensor is bad or that its on the way out? The sensor list says "slow response". What does that mean?

DennisMik

iTrader: (2)

The front heated oxygen sensor is placed into the exhaust manifold. It detects the amount of oxygen in the exhaust gas compared to the outside air. The front heated oxygen sensor has a closed end tube made of ceramic zirconia. The zirconia generates voltage from approximately 1V in richer conditions to 0V in leaner conditions. The front heated oxygen sensor signal is sent to the ECM. The ECM adjusts the injection pulse duration to achieve the ideal air-fuel ratio. The ideal air-fuel ratio occurs near the radical change from 1V to 0V.

The cycle of the voltage signal from the sensor is more than
the specified time, i.e., "slow response".

While it most likely is the O2 sensor going bad, it could also be other things.
* Harness or connectors (The sensor circuit is open or shorted.)
* Front heated oxygen sensor
* Front heated oxygen sensor heater
* Fuel pressure
* Injectors
* Intake air leaks
* Exhaust gas leaks
* PCV
* Mass air flow sensor

PH98I30

Thank you for you reply. I know from other posts that you are very knowledgeable. The O2 sensosr have never been changed and I have 132K on the clock. I have the previous owners records and there is no mention of O2's being replaced. BTW, I love this car. It has been nearly trouble free for the 3 years I have owned it.