Hello all,

My engine light came on the other day and after scanning it has reported a P0131 fault (O2 Sensor Circuit Low Voltage Bank 1, Sensor 1)

I had a P0130 fault around August last year and ended up replacing both O2 sensors. So it has only been 6 months and a similar fault has appeared again; I haven't even driven the car that much!

From a quick search I understand its the same fault as the P0130 but the opposing O2 sensor.

I don't want to replace both O2 sensors so was hoping you could help identify which sensor I need to replace. See photos atatched; one is at the top before connecting to the Cat (green connector) and the other is underneath (black connector). Hopefuly it is the O2 sensor underneath as that is much easier to replace!

Any help welcome, thank you in advance!

 

That refers to the Sensor before the Cat and is a generic code, and the Sensor may not necessarily be faulty. Generic Code Readers are of limited use on a modern car.

It would be wise to invest a modest amount on getting set up with FORScan and checking if there are any more Ford specific codes as well and have the ability to monitor Live Data if necessary after doing some more research. 

12 minutes ago, Tizer said:

That refers to the Sensor before the Cat and is a generic code, and the Sensor may not necessarily be faulty. Generic Code Readers are of limited use on a modern car.

It would be wise to invest a modest amount on getting set up with FORScan and checking if there are any more Ford specific codes as well and have the ability to monitor Live Data if necessary after doing some more research. 

Hi, thanks for your reply

I'm assuming the bottom O2 is before Cat?

If the O2 sensor may not necessary be faulty, what would you reccomend I do first before replacement?

2 minutes ago, maton91 said:

Hi, thanks for your reply

I'm assuming the bottom O2 is before Cat?

If the O2 sensor may not necessary be faulty, what would you reccomend I do first before replacement?

No, it is the one nearest the engine.

I wouldn't recommend anything other than what I said before other than checking that there are on obvious wiring faults.

1 hour ago, maton91 said:

Hello all,

My engine light came on the other day and after scanning it has reported a P0131 fault (O2 Sensor Circuit Low Voltage Bank 1, Sensor 1)

I had a P0130 fault around August last year and ended up replacing both O2 sensors. So it has only been 6 months and a similar fault has appeared again; I haven't even driven the car that much!

From a quick search I understand its the same fault as the P0130 but the opposing O2 sensor.

I don't want to replace both O2 sensors so was hoping you could help identify which sensor I need to replace. See photos atatched; one is at the top before connecting to the Cat (green connector) and the other is underneath (black connector). Hopefuly it is the O2 sensor underneath as that is much easier to replace!

Any help welcome, thank you in advance!

 

 

Hi - Tizer speaks wisely - see if you can find the actual fault - don't necessarily trust a generic garage, who usually fix faults by replacing items until the fault goes away.  See if you can find someone locally who is an emissions/electric specialist, if you can't get the FORScan yourself.

Also last August, how did you find out it really was the original O2 sensors that were throwing the P0130?

But an engine rebuilder specialist who recently did some work for me (on another car) who really really knows about emissions and CATs said that the aftermarket 02 sensors fall into two categories - cheap or good. (edited to be clearer)

Which make did you fit last year?  If they were cheap (and they were the actual problem in August) then I'm afraid that might still be your problem.  He fits NTKs which are expensive.

OPIE sell them, so they must be good.

20 hours ago, orangecurry said:

Hi - Tizer speaks wisely - see if you can find the actual fault - don't necessarily trust a generic garage, who usually fix faults by replacing items until the fault goes away.  See if you can find someone locally who is an emissions/electric specialist, if you can't get the FORScan yourself.

Also last August, how did you find out it really was the original O2 sensors that were throwing the P0130?

But an engine rebuilder specialist who recently did some work for me (on another car) who really really knows about emissions and CATs said that the aftermarket 02 sensors fall into two categories - cheap or good. (edited to be clearer)

Which make did you fit last year?  If they were cheap (and they were the actual problem in August) then I'm afraid that might still be your problem.  He fits NTKs which are expensive.

OPIE sell them, so they must be good.

Hi thanks for your reply

I replaced both O2 sensors back in August as I didn't know which one reported the fault. I don't remember which brand I used but they were middle priced so not the cheapest but not the dearest 

Once both O2 sensors were replaced the engine management light never returned once I cleared it with my OBD so presumed it was one of the O2 sensors that were causing the fault. Before replacing I cleared the fault and after a couple of miles driving the engine management light returned so knew there was something not right

Coincidentally I had a service last week and the engine management light appeared a few days after. After seeing your post to look at the O2 sensor, when I disconnected it unclicked pretty easily so I am now wondering if it was just loose and the service engineer inevertently loosened the connection.

So I've reconnected properly and cleared the fault. I'm going to take the car for a spin next week for at least 20 miles so would expect the engine management light to return if the fault is still present

This FORScan software, am I right in saying it is software on your laptop? If so how much is it and how do I connect my laptop to my car's ECU? My car has a D type outlet which I connect my OBD scanner to so guess there is a USB to D type cable to use?

1 hour ago, maton91 said:

Hi thanks for your reply

I replaced both O2 sensors back in August as I didn't know which one reported the fault. I don't remember which brand I used but they were middle priced so not the cheapest but not the dearest 

Once both O2 sensors were replaced the engine management light never returned once I cleared it with my OBD so presumed it was one of the O2 sensors that were causing the fault. Before replacing I cleared the fault and after a couple of miles driving the engine management light returned so knew there was something not right

well.... not really.  You say you haven't used the car much since August.

If an 02 sensor is showing a fault, this could be a real fault upstream. That's what the sensors are for.

There are dozens of things in a modern engine that may go wrong which would push emissions over the threshold.

If the problem is 'small' and only just over the threshold to throw a fault code depending on the weather/temp/long-short-journey etc etc etc, then once cleared, the fault-code will go away for days/weeks/months.

Also maybe the original sensor was coated with crap, so just replacing it will delay your seeing the code return?

Sorry but until you actually find out what the fault is, (and yes it could still be a sensor) you are in the dark.  I've never used FORScan, but if it gives real-time data, or more information than the generic OBD2 reader, then it will tell you what the issue is, not just 'sensor x is reading out of range'.

2 hours ago, maton91 said:

This FORScan software, am I right in saying it is software on your laptop? If so how much is it and how do I connect my laptop to my car's ECU? My car has a D type outlet which I connect my OBD scanner to so guess there is a USB to D type cable to use?

The standard version of FORScan is Free. It allows you to do most things but some programming requires you to buy a licence which is worth it for only £10

Download FORScan: https://forscan.org/download.html

You will also need one of the new style leads to connect your laptop to the OBDII port on the car.

New vLinker FS lead available from here (£35): https://www.bmdiag.co.uk/forscan-diagnostic-cable-for-ford-vgate-vlinker-fs

Always back-up and save a copy of any module before you use FORScan to make programme changes.