K12 upstream and downstream O2 sensor replacement

Hi, first post here.

My other car, a 56 plate K12 with 40k miles is running rough and showing an error with O2 Bank 1. I see from internet posts that usually both sensors go. How easy are they to replace? I'm reasonably confident and have a good tool kit, but my other car and previous cars have all been diesels so never even looked at an O2 sensor before.

tnx in advance

Nik
 

skymera

Brutal Honesty
Fairly simple. You'll no doubt have one in the exhaust manifold and one after the cat usually under the car.

Just need a big spanner and some elbow grease :)

Sent from my HTC One using Tapatalk
 
Welcome

First Post Approved

I hope you find what you need and stick around, it will be worth it :)

Thank you. I'm sure I will. I'm used to using internet forums to fix cars and after owning a Range Rover, I've spent an awful lot of time online and under the car!! However, the Micra has been extremely reliable for all its 40k miles. Therefore I've never needed Micra help before now. I do have the Micra K12 Electronic Service Manual now and have found the location of the O2 sensors and the one that's complaining is in the engine bay and looks simple enough. The only question is do I get one from Eurocarparts or Nissan? Big difference in price. I would normally get Eurocarparts for filters etc, but not sure about sensors...

tnx!

Nik
 

SirChris

Educated Bodger
ermm... i try tio avoid nissan unless they are critical stuff... e/g head gaskets and filters. other wise with 02 sensors I go euro car parts but buy a high quality one
 
Right, replaced O2 Bank 1 sensor 1 with a NTK which was EXACTLY the same as the sensor that came out. Cleared the fault. Runs lovely, but within a few miles of driving, the exact same fault comes back. So it clearly isn't O2 Bank 1 Sensor 1. It must be throwing that error because of something else. Do I need to change the one after the CAT to? The wiring seems ok. I've had all plugs off (inc the ECU) and cleaned them in contact cleaner. I've gone as far as I can go without any pointers.

Any ideas?

tnx

Nik
 

frank

Club Member
fuel trim issue maybe nik ? that lambda sensor basically monitors the fuel/air ratio, so it may be a fueling fault ?
 
On the drive this morning:
STFT at idle is between +1.6% and -3.6% but that will jump up to -8.7% as I accelerate.
LTFT is 0%
But I don't know if the diagnostics will read historical stored values or if they are all for that session - in which case I'd need to take it for a drive and put it under load...

Nik
 
Don't forget to disconnect the battery and reset the clock in the cluster display. Oddly that's what switched engine light off for mine once lambda had been changed. If you can avoid changing it without needing to remove the exhaust,I'd say your on to a good one,that was the evil part on mine. Needed to remove the cat,alternator,and manifold in the end,but that was due to corroded bolts,hope yours goes better :)
 
Why do I need to reset? Is that to reset all the fuel trims or just to turn the CEL off? If the latter, I've turned it off with Torque.

It was actually really easy to replace. I did it as soon as I got in from work.

I spoke to a Nissan tech today who confirmed that its normally the rear one that goes even though it reports the front one, so fingers crossed I'm all done. I'll know tomorrow after its been used. I might have wasted £87 on the front sensor, but still cheaper than a trip to Nissan :)

Tnx all

Nik
 
My enginge management light came on,and then I dicovered my post cat lambda had split in half. Once I got it all replaced (my downpipe,and cat were nearing end of life so replaced all the same time) the engine light stayed on. Fearing it was something further still amiss,I left it for a couple days,went to drive off one morning and decided to reset the clock,and the light went out. I don't have the kit for reading/resetting codes see,so without realising that you have,and sort of not reading all previous posts on this thread,just thought I'd give my little input on switching the light off. Glad yours is all sorted,for their faults,they are a great little car :)
 
Just to update you, replacing the downstream sensor fixed it. The error has not re-occured and the car is purring like a kitten. If you get a failure on O2 Bank1 Sensor1, don't waste your money replacing it, replace Sensor2 - the one after the CAT instead and you'll be fine.

Nik
 
Hello Ive just joined thanks!

I have the same problem could anyone upload a pic of where the rear sensor is please?
Also I read that if you renew them you have to take the car to a dealer to get the light reset, that does not seem to be needed going by what you have wrote here. I have torque and an obd2. So I should just disconnect battery, replace sensor, turn of EM light and reset clock is that right??
Thanks in advance for any help, I know its an old thread.
 
Hello Ive just joined thanks!

I have the same problem could anyone upload a pic of where the rear sensor is please?
Also I read that if you renew them you have to take the car to a dealer to get the light reset, that does not seem to be needed going by what you have wrote here. I have torque and an obd2. So I should just disconnect battery, replace sensor, turn of EM light and reset clock is that right??
Thanks in advance for any help, I know its an old thread.
If you look under the car around the drivers side front wheel you can see the O2 sensor there,the first O2 sensor is on the manifold and is easily seen at the front of the engine with the bonnet open and the air feed pipe lifted up. The ECU is self learning once a sensor is replaced,may take a day or two for it to pick up the sensor change,but it will just clear the light itself

Sent from my EVA-L09 using Micra Sports Club mobile app
 
Update- managed to take out sensor 2 and give it a clean, carb spray. Cleared fault using torque light went out. Torque read no faults. Later next day light went back on but instead of showing both 032 and 037 fault it just shows 037. My problem is is it worth paying for the tool to get sensor 1 out knowing I may as well try renewing sensor 2 first.
 
On the drive this morning:
STFT at idle is between +1.6% and -3.6% but that will jump up to -8.7% as I accelerate.
LTFT is 0%
But I don't know if the diagnostics will read historical stored values or if they are all for that session - in which case I'd need to take it for a drive and put it under load...

Nik

Wide open throttle tests are good since the ecu does not use the 02 sensor signal input in most cars and uses the maximum fuel/air mixture which is a quick and dirty way to tell if the 02 sensors are working...
 
Wide open throttle tests are good since the ecu does not use the 02 sensor signal input in most cars and uses the maximum fuel/air mixture which is a quick and dirty way to tell if the 02 sensors are working...

Hi Max,

I have a nagging problem with my K12 that is well documented in the discussion "Engine only runs with throttle position sensor disconnedted??"
The title of which is misleading.

In short, the car will not start when cold in the morning, but once started with some difficulty (with a squirt of petrol on air filter) runs and starts perfectly all day.
This sounds like "cold start enrichment" so changed the coolant temp sensor with no change. Also get the correct fault code when the temp sensor is disconnected, so the wiring seems to be OK.

I have also change many other sensors, CAM and Crank position, MAF, Throttle body,fuel pump, and even ECU, non of which worked.

But I have not changed the oxygen nor lambda sensors. Do you think its worth a punt changing one or both of these? But they are not cheap and don't really want to throw good money after bad.

The fuel on filter workaround has been ok in summer but not sure how this will work in cooler weather??

Any ideas you have would be much appreciated,
Mark
 
Just to update you, replacing the downstream sensor fixed it. The error has not re-occured and the car is purring like a kitten. If you get a failure on O2 Bank1 Sensor1, don't waste your money replacing it, replace Sensor2 - the one after the CAT instead and you'll be fine.

Nik
What's the location of that sensor please as I've had the same error and time replaced the one near the oil filter but the light came back on
 
Just to update you, replacing the downstream sensor fixed it. The error has not re-occured and the car is purring like a kitten. If you get a failure on O2 Bank1 Sensor1, don't waste your money replacing it, replace Sensor2 - the one after the CAT instead and you'll be fine.

Nik
What's the location of that sensor please as I've had the same error and time replaced the one near the oil filter but the light came back on
 
Update- managed to take out sensor 2 and give it a clean, carb spray. Cleared fault using torque light went out. Torque read no faults. Later next day light went back on but instead of showing both 032 and 037 fault it just shows 037. My problem is is it worth paying for the tool to get sensor 1 out knowing I may as well try renewing sensor 2 first.
Hello k12User, I’m having the same issue and have no experience doing this stuff. I need to get to the second downstream sensor, can you point me in the correct location for it or have a picture? Thanks in advance.
Update- managed to take out sensor 2 and give it a clean, carb spray. Cleared fault using torque light went out. Torque read no faults. Later next day light went back on but instead of showing both 032 and 037 fault it just shows 037. My problem is is it worth paying for the tool to get sensor 1 out knowing I may as well try renewing sensor 2 first.
 
Just to update you, replacing the downstream sensor fixed it. The error has not re-occured and the car is purring like a kitten. If you get a failure on O2 Bank1 Sensor1, don't waste your money replacing it, replace Sensor2 - the one after the CAT instead and you'll be fine.

Nik
Hi Nik, is the rear sensor accessible without jacking the car up?
Thanks
Alan
 
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