Re-occurring P0136 after replacement

[Jaffacakes]

Hi all, been a while since I posted, but its also been a while since I've had any problems with the two!

A few weeks ago I had the engine light come on driving home from work and after my heart stopped pounding, I noticed no unusual noise and it was driving just fine, I completed my journey home, whipped out the code reader and found that it was just P0136 Sensor 1 Bank 2. Looked it up on here on the search and found that this was the post-cat O2 sensor and it was no biggie.

I did clear the code and drove for a bit and it came back on.

So I bought a brand new Denso DOX-0206 from OpieOils through ebay for £50ish and got it through a few days later. I was going to fit it myself, but any time I've been home in the light its been a tad wet and I didn't fancy getting under the car to fit it, though it looked like a straightforward job.

As it happened I was having two new Yoko Advan AD08s fitted on the rear through blackcircles at M-Tech in Hastings and I asked if they sort it for me whilst in which they duly did for £20, so was happy with that.........UNTIL driving home again and the engine light came back on!

Checked code when I got home and was same P0136 again. I thought perhaps M-Tech had made a booboo and forgotten to actually fit the sensor, but looking under the hood, the sensor I can see down the passenger side below the rear light looks shiny and new, as does the wire and plug (behind the rear passenger light?).

So, do you think I got a duff sensor or is there something I should be trying/doing?

I will drop OpieOils a line, but as I don't have the old sensor, taking it off to send back for replacement will be a PITA, not to mention again how wet it is lately and finding time to do it.

Let me know if any of you have any thoughts.

Cheers
Geoff

[Carolyn]

You could try disconnecting the connector and spraying with some contact cleaner.  Could be a connectivity issue. You could also check the voltages.   I'm sure someone like Schnazzle will know what voltage readings you should be getting from the connector going to the harness.  I know it's 12v for the heater.. the actual sensor circuit I'm not so sure.

[jonbill]

I think you're looking for between 1 and 5v across the 2 wires that aren't the same colour on the harness plug.
If that's there I think duff sensor or connection problem.

[Jaffacakes]

Not to sound like a total numpty, but how would I go about checking the voltage exactly? I can probably lay my hands on a meter, but I've no idea how to use it! I might have some contact spray somewhere from when I bought a can to clean the MAF, same stuff? Do I just spray it into the connector/plug and let it evap? It was a new sensor so ought to be clean...
Cheers
Geoff

[jonbill]

yes, get a multimeter, put it on an appropriate voltage range, turn the ignition on and touch the relevant contacts in the harness plug with the meter probes. (doesn't matter which way round).
wrt your contact cleaner, it's the harness plug that might need cleaning  :-) :-) :-)

[Jaffacakes]

Righto, ta, I will take a look some point in the week when I can find the multimeter  s:) s:)

Geoff

[m1tch]

If you have an OBD reader and the torque app you can see if all of the sensors are giving a reading - all 3 of my sensors were throwing a code, however 2 of them were showing a voltage when they were warmed up. I found that 1 O2 sensor was shot and the other 2 had failed heater elements but worked fine, replaced the post cat sensor and the car runs well - still throws a code due to the heater issue but can be bypassed with a resistor as the sensor itself is fine, just doesn't self warm.