marz

Maybe someone with C6 experience can give me some advice. I have a check engine light on in my car. Had it scanned and it showed Bank 2 sensor and whatever else this could mean. I have changed out the Mass Air Flow sensor and the pre-cat O2 sensor on the driver's side, but the light is still on. Do I need to change sensors on both sides when I change out one?

Getting to be mighty expensive guesses. I did a search here and it people all said the pre-cat sensor was the problem most of the time.

Any advice? This is a 2008 model.

Thanks.

ChevyDave

P0050 HO2S Heater Control Circuit Bank 2 Sensor 1 ECM
P0056 HO2S Heater Control Circuit Bank 2 Sensor 2 ECM
P0151 HO2S Circuit Low Voltage Bank 2 Sensor 1 ECM
P0152 HO2S Circuit High Voltage Bank 2 Sensor 1 ECM
P0153 HO2S Slow Response Bank 2 Sensor 1 ECM
P0154 HO2S Circuit Insufficient Activity Bank 2 Sensor 1 ECM
P0155 HO2S Heater Performance Bank 2 Sensor 1 ECM
P0156 HO2S Circuit Bank 2 Sensor 2 ECM
P0157 HO2S Circuit Low Voltage Bank 2 Sensor 2 ECM
P0158 HO2S Circuit High Voltage Bank 2 Sensor 2 ECM
P0160 HO2S Circuit Insufficient Activity Bank 2 Sensor 2 ECM
P0161 HO2S Heater Performance Bank 2 Sensor 2 ECM
P1153 HO2S Insufficient Switching Bank 2 Sensor 1 ECM
P1154 HO2S Transition Time Ratio Bank 2 Sensor 1 ECM

which of these codes was it? (did you reset/clear codes after 'fixes'?)


P0158 02 Sensor Circuit High Voltage (Bank 2 Sensor 2)
www.obd-codes.com/p0158
A P0158 refers to a fault at the post-cat o2 sensor on bank 2 (second sensor back ... will normally switch slower and fewer times than front (pre-cat) o2 sensors.

P0160 02 Sensor Circuit No Activity Detected (Bank 2 Sensor 2)
www.obd-codes.com/p0160
This particular o2 sensor on Bank 2, position 2 is after the converter on bank 2 and ... post-cat o2 sensor to the pre-cat o2 sensors to measure the cat's efficiency.

P0157 02 Sensor Circuit Low Voltage (Bank 2 Sensor 2)
www.obd-codes.com/p0157
This code refers to a fault in the post-catalyst o2 sensor on Bank 2. First ... in post- and pre- catalyst sensors then it knows that the catalyst is not working properly

marz

It was this code. P0158 02. No, I have not rescanned it. Will do that next.

Thanks.

ChevyDave

just a f.y.i. , i looked up replacement and they stated...

Due to the potential differences in accuracy between new and old sensors, you should always replace BOTH pre-cat sensors or BOTH post-cat sensors or you may cause more problems than you solve.

honestly i dont know if above quote is legit or not. just passing what i read.

Also i believe P0158 refers to Bank 2 sensor 2 which is the passenger side rear O2 sensor (post-cat).... not pre-cat front on driver side.

SUB VETTE

Have you installed headers on this car?

marz

No headers on this one. I went ahead and changed out both pre-cat and reset and check engine light is off now. these C6 models are strange puppies.

Thanks for the help guys!

ChevyDave

great!!!!!!!!!!! my only concern is that you said pre-cat. i keep thinking that your code... P0158 refers to Bank 2 sensor 2... means bank 2 (cylinders 2,4,6,8) passenger side and sensor 2... means after the catalyst nearest back of the car. pre-cat would be before catalyst.
(i aint no expert, shade tree i are)

wishing ya the best!!!

548chevelle

Since the ECU is keeping the heater on too long and causing it burn out maybe adding some external resistance to the circuit would cut down on the current that's passing thru the sensor heater. I measured the heater resistance at about 6 ohms. Adding a 1 ohm resister in series with the heater circuit would cut the amperage about 10-12%. this MIGHT let the heater live longer. I just gave an example. I have no idea what might actually be an optimum value. But then a code might come up because the ECU tests how long it takes the sensor to heat up. Less current and it will take longer. But there might be sweet spot where less current saves the heater and passes the sensor test.
Another way to reduce the current is with a diode in series. A 1N5401 would drop the current about 5%. Two in series drops about 10%. They're a lot cheaper at around 40 cents. Just saying.