P0138 code - Peugeot 207
Discussion
Had a P0141 code (O2 Sensor Heater Circuit Malfunction Bank 1, Sensor 2). Changed the oxygen sensor which was in a bad way and that has been resolved.
Now I am left with a P0138 code (O2 Oxygen Sensor Circuit High Voltage Bank1, Sensor2) but am unsure what the problem could be.
Engine idles rough and there is a strong smell of petrol when I first start the car.
I must add the 'depollution system faulty' message has appeared for at least 6 months and I have ignored it like an idiot and now I'm paying the price.
Any ideas?
Now I am left with a P0138 code (O2 Oxygen Sensor Circuit High Voltage Bank1, Sensor2) but am unsure what the problem could be.
Engine idles rough and there is a strong smell of petrol when I first start the car.
I must add the 'depollution system faulty' message has appeared for at least 6 months and I have ignored it like an idiot and now I'm paying the price.
Any ideas?
Things that can cause Lambda issues:
Unmetered air leak - likely from intake tubing & can be hard to find, try spraying carb-cleaner carefully & see if any is sucked in, you will hear the idle change. A good play with any intake hoses/vac pipes etc should find it if it is there.
Poor combustion - When was it last serviced/plugs/filters changed/oil & filter changed/PCV cleaned/checked/EGR cleaned/checked.
Goosed cat - hopefully not, rule out the easy/cheap first.
Alternatively get it in to a trusted garage & have them diagnose the issue if you can't do the above.
Unmetered air leak - likely from intake tubing & can be hard to find, try spraying carb-cleaner carefully & see if any is sucked in, you will hear the idle change. A good play with any intake hoses/vac pipes etc should find it if it is there.
Poor combustion - When was it last serviced/plugs/filters changed/oil & filter changed/PCV cleaned/checked/EGR cleaned/checked.
Goosed cat - hopefully not, rule out the easy/cheap first.
Alternatively get it in to a trusted garage & have them diagnose the issue if you can't do the above.
I'm doing a vehicle tech course, and one thing i get hammered into me with things like this, since they are relatively cheap is buy a genuine one only!
Aftermarket ones can be utter crap, or at the very best don't perform the same.
If the o2 sensor before the cat has failed and is showing a constant 'lean' condition, the fuel trim will then adjust it's signal to your engine computer which will then throw in petrol to adjust for the lean condition!
If you run it like this for a while you will bugger your catalytic converter!
Just take it to a garage, and ask what the readings are like on your upstream o2(one before the cat) and the downstream o2(just after the cat, one you've replaced) will take them 5 minutes.
If the cat is buggered,you can test this possibility by removing the upstream o2 (before the cat) altogether temporarily to see if it runs better, it should run better if the cat is blocked!
Aftermarket ones can be utter crap, or at the very best don't perform the same.
If the o2 sensor before the cat has failed and is showing a constant 'lean' condition, the fuel trim will then adjust it's signal to your engine computer which will then throw in petrol to adjust for the lean condition!
If you run it like this for a while you will bugger your catalytic converter!
Just take it to a garage, and ask what the readings are like on your upstream o2(one before the cat) and the downstream o2(just after the cat, one you've replaced) will take them 5 minutes.
If the cat is buggered,you can test this possibility by removing the upstream o2 (before the cat) altogether temporarily to see if it runs better, it should run better if the cat is blocked!
Edited by robbocop33 on Thursday 28th March 19:12
Edited by robbocop33 on Thursday 28th March 19:13
I'm doing a vehicle tech course, and one thing i get hammered into me with things like this, since they are relatively cheap is buy a genuine one only!
Aftermarket ones can be utter crap, or at the very best don't perform the same.
If the upstream (before cat) o2 sensor has failed in the past and wass showing a constant 'lean' condition, the fuel trim will then adjust it's signal to your engine computer which will then throw in petrol to adjust for the lean condition!
If you run it like this for a while you will bugger your catalytic converter!
Just take it to a garage, and ask what the readings are like on your upstream o2(one before the cat) and the downstream o2(just after the cat, one you've replaced) will take them 5 minutes.
If the cat is buggered,you can test this possibility by removing the upstream o2 (before the cat) altogether temporarily to see if it runs better, it should run better if the cat is blocked!
Aftermarket ones can be utter crap, or at the very best don't perform the same.
If the upstream (before cat) o2 sensor has failed in the past and wass showing a constant 'lean' condition, the fuel trim will then adjust it's signal to your engine computer which will then throw in petrol to adjust for the lean condition!
If you run it like this for a while you will bugger your catalytic converter!
Just take it to a garage, and ask what the readings are like on your upstream o2(one before the cat) and the downstream o2(just after the cat, one you've replaced) will take them 5 minutes.
If the cat is buggered,you can test this possibility by removing the upstream o2 (before the cat) altogether temporarily to see if it runs better, it should run better if the cat is blocked!
Edited by robbocop33 on Thursday 28th March 19:12
Edited by robbocop33 on Thursday 28th March 19:33
I had a mechanic look at it yesterday and he basically said the same as you and advised me to buy a Bosch one.
Showed me the voltage readings, the upstream one was fluctuating a lot between 0.1 - 0.9V whereas the downstream one (that I'd changed) was steady at 0.9V. He said it should also be fluctuating.
So I've bought a Bosch one, will change it tomorrow and hopefully it will solve the problem!
Showed me the voltage readings, the upstream one was fluctuating a lot between 0.1 - 0.9V whereas the downstream one (that I'd changed) was steady at 0.9V. He said it should also be fluctuating.
So I've bought a Bosch one, will change it tomorrow and hopefully it will solve the problem!
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