O2 sensor replaced, CEL still present... Topic is solved

Oakman1 · Post by **Oakman1** » 09 Oct 2016, 01:49

Hi All,
I have a 2001 v70 2.4 non-turbo that has a CEL and a trouble code of p0032. I've replaced the sensor (I'm fully aware it could be other things manifesting themselves as a bad o2 sensor, but I'm in rush mode to get this fixed for smog purposes), being an armchair mechanic, I expected the CEL to turn off immediately. I've since learned that I'll likely have to do a "drive cycle" to get the emissions systems to reset themselves. I've read the finer points on drive cycles, but my question is, do I turn the CEL off with my code reader, complete the required cycles and hope it never comes on? Or do I leave the CEL illuminated as it is and expect (if I did indeed fixed the issue by replacing the sensor) it to turn off by itself?
I do have to say that the v70 has been a bit of a nightmare. Always something with this car.
Thanks for the assist everyone.
-Evan

Post by **kranz** » 09 Oct 2016, 02:00

You must use the code reader to turn off the CEL light. Then a new drive cycle will begin to test your remedy.

beigg · Post by **beigg** » 09 Oct 2016, 09:35

Oakman1 wrote:Hi All,
I have a 2001 V70 2.4 non-turbo that has a CEL and a trouble code of p0032. I've replaced the sensor (I'm fully aware it could be other things manifesting themselves as a bad o2 sensor, but I'm in rush mode to get this fixed for smog purposes), being an armchair mechanic, I expected the CEL to turn off immediately. I've since learned that I'll likely have to do a "drive cycle" to get the emissions systems to reset themselves. I've read the finer points on drive cycles, but my question is, do I turn the CEL off with my code reader, complete the required cycles and hope it never comes on? Or do I leave the CEL illuminated as it is and expect (if I did indeed fixed the issue by replacing the sensor) it to turn off by itself?
I do have to say that the V70 has been a bit of a nightmare. Always something with this car.
Thanks for the assist everyone.
-Evan

You must command a system reset for that code even if the mechanical portion was remedied correctly. It's a "one-way" fault detecting system. Once tripped, you must reset it yourself. Similar concept as a GFCI or RCD outlet.

Oakman1 · Post by **Oakman1** » 09 Oct 2016, 10:28

Hey thanks for the reply.
How would I go about commanding a system reset? I've done the "disconnect your battery for 15 mins" and "erase everything with your obd scanner."
I really appreciate the assist.

beigg · Post by **beigg** » 09 Oct 2016, 18:41

obdII scan tool

Oakman1 · Post by **Oakman1** » 09 Oct 2016, 21:34

beigg wrote:obdII scan tool

Shoot, this leads me to believe I didn't fix the problem, as I've already turned off the CEL light with this method and the light returns with the same trouble code.

Post by **abscate** » 10 Oct 2016, 03:51

Have a good look at the connectors for the OXS. The code is for a heater circuit failure, which can be in wiring or connector.

beigg · Post by **beigg** » 10 Oct 2016, 03:56

make sure you replaced to correct one. Its easy to mismatch pigtails. Pre-owner might have r&r'd both sensors, accidentally swapping harness ends.

Post by **vtl** » 10 Oct 2016, 19:02

What kind of sensor went in? It needs Denso with a proper part number.

Oakman1 · Post by **Oakman1** » 22 Oct 2016, 00:36

Ok y'all time for an update. Sorry for the very late response, very busy at work and school.
I went to a wrecker and found my model car and took the sensor off and installed it on mine. It shut the CEL off thankfully. Now the issue I'm running into is drive cycle stuff. Only 6 out of the 10 readiness monitors are ready. HCM, 2 Air, A/C, and EGR aren't ready. That's with 300 miles of driving. What could cause those particular monitor to not be ready after 300 miles of driving? I took a look and the downstream o2 sensor and I found that the original owner replaced it with a universal, splice in type. There's no CEL on for it and my OBD2 reader i showing no DTC codes. Should I swap out the downstream o2? I realize that won't take care of all my issues but is there a monitor that I listed that might be affected by that?
This forum is great, and I learned a great lesson to only go with OEM parts for Volvo's.