Testing O2 Sensors

[jack.mc]

Hey guys,

Before you tell me to do a diagnostics test...

I got extractors installed half way through last year . I got code 13 soon after (assumed sensor hasn't survived the move) so I got a new sensor. Still got code 13 . I tried sanding the extractor thread (internal) to make sure the sensor was earthing - it was, still more code 13s. I bought an ALDL cable to grab the data - was told to get a heated sensor. None of the workshops reccomend this (but its still an option, top of the list at the moment). My fuel consumption gets worse with each tank, literally every tank seems worse than the last :b:. I really dont want to go to an auto-electrician.

Its starting to get to me, and I've started twitching every time 'O2 Sensor' is mentioned. Please have a look at the data in the link in my sig, or if you know any way that i can test the new sensor to make sure it isn't a faulty one, let me know.

It is pissing me off majorly . I may as well be driving an 8!

thanks for reading this, hope you can help

[mouce]

With the heat that the O2 sensor has to put up with, it's quite possible for the wire to become brittle over time, it could just be a busted wire.

One of my mates at uni had that on his VN wagon, kept getting code 13, kept changing the O2 sensor, and it didn't fix anything. Turned out that the wire had cracked and wasn't conducting any more. Might be worth checking.

[jack.mc]

so the wire after the connecter, to the ECU? how do i check that? It could be that, as the wire had to be moved a fair bit to get it to reach the extractors

[lazza44]

I am having the exact problem on my vns2. got extractors.....................blabla..I did all the tests in the gregory's manual and they came up fine. I also checked the continuity of the two cables going from the ecu to the plug and there is continuity. I get code 13 usually when cruising at the same speed above say 70kmph. The engine light usually comes on after about 8mins of driving and stays on for about 10secs. Happens about every second trip. My sensor is about 4months old and I havent used any harmful sealants etc. when does your light come on??

[jack.mc]

Mine comes on at random intervals - i havent had it for about 2 weeks. When it does come on, its often within a few minutes of starting, when i'm doing nothing special.


When it is working properly, is it meant to be closed or open loop? Thanks

[Cheap6]

O2 sensor is used for closed loop control.

Best 2 check voltages at ECM, then work back from there. Don't know which pin off the top of my head but it can be found by googling '1227165', the US version of the 1227808 ECM used in Commodores, and looking for pin out data - the wires and colours are the same.

Plenty of previous posts on O2 sensors in this forum.

To answer the question in the original post regarding testing the sensor: Maybe find a mate/relative with the same model Commodore/engine, swap the sensors and watch the voltage outputs when driving in each.

[ssute57l]

Just cause the fault says O2 sensor this is not always the case, there could be another fault like coolant temp sender etc causing eng to run rich and giving you a faulty O2 sensor reading when it is fine.