nox/scr catalyst monitor bank 1 code

[Newpicman]

Hi all, new to this site after searching regarding an error I have through my obd reader.
Went to work the other day and twice I had an error pop up saying electrical fault.
After getting home I plugged my OBD reader in and checked for faults.
Got 1 fault which was nox/scr catalyst monitor bank 1.
When I searched 1 of the possible problems could be insufficient ad blue. No low warning messages had popped up recently so assumed there was enough ad blue. The last time I topped up with ad blue was about 3 years ago(now looking in to it I see there's no way after doing approximately 25k that any ad blue would be left)
I have added 10 litres of ad blue done approximately 60 miles and done another diagnostic and still getting the same error.
Wondered if the ad blue level sensor has gone with not getting a 1500 mile warning but thinking it may also be something else with the same error code coming up.
Any info much appreciated
Thanks.

[Doo]

Hi all, new to this site after searching regarding an error I have through my obd reader.
Went to work the other day and twice I had an error pop up saying electrical fault.
After getting home I plugged my OBD reader in and checked for faults.
Got 1 fault which was nox/scr catalyst monitor bank 1.
When I searched 1 of the possible problems could be insufficient ad blue. No low warning messages had popped up recently so assumed there was enough ad blue. The last time I topped up with ad blue was about 3 years ago(now looking in to it I see there's no way after doing approximately 25k that any ad blue would be left)
I have added 10 litres of ad blue done approximately 60 miles and done another diagnostic and still getting the same error.
Wondered if the ad blue level sensor has gone with not getting a 1500 mile warning but thinking it may also be something else with the same error code coming up.
Any info much appreciated
Thanks.

I can't be certain as the pigpiss is a new concept to me (I mean, who even THOUGHT that up? ) but I do believe there is a known issue where the pumps pack in (somehow usually ay 120k miles.....almost as if they've been programmed from the factory to do so.....like the electric power steering modules that have been programmed to pack in after 1000,000 turns of the steering wheel BUT, who am "I" to suggest the manufacturers would resort to such dirty tactics

Might be worth getting the system interrogated & letting it know a "new" cat has been inserted (even though it "hasn't!" the system won't know until it has been "informed!"

Money, money, money

[CitroJim]

I can't be certain as the pigpiss is a new concept to me (I mean, who even THOUGHT that up? )

The chemistry makes sense... Urea (a significant portion of mammalian urine) decomposes to ammonia in the heat of the exhaust and in the cat it turns harmful NOx compounds into harmless nitrogen and water...

But yes, the Adblue system as engineered by PSA may not be the best but then again, the offerings from others are not exactly wonderful either...

The problem stems from the tendency for Adblue to crystallise and these crystals can block things up.

It might be worth dosing the Adblue tank with a bottle of (e.g.) Wynns Crystal Clear and Protect but this may not help with a clogged one as yours may now be but it's worth a go.

It may also be a good preventative...

Your problem may be the urea injector being blocked with crystals... I understand it's not a big job to replace it.

[RichardW]

I wouldn't trust those codes - you need it on a better scanner.

An adblue fault won't give you a 'Electrical fault' warning so something else is going on. And if you haven't put any Adblue in it for over 25k miles, then almost certainly someone has been there before you and deleted the system....

[Newpicman]

Hi all, new to this site after searching regarding an error I have through my obd reader.
Went to work the other day and twice I had an error pop up saying electrical fault.
After getting home I plugged my OBD reader in and checked for faults.
Got 1 fault which was nox/scr catalyst monitor bank 1.
When I searched 1 of the possible problems could be insufficient ad blue. No low warning messages had popped up recently so assumed there was enough ad blue. The last time I topped up with ad blue was about 3 years ago(now looking in to it I see there's no way after doing approximately 25k that any ad blue would be left)
I have added 10 litres of ad blue done approximately 60 miles and done another diagnostic and still getting the same error.
Wondered if the ad blue level sensor has gone with not getting a 1500 mile warning but thinking it may also be something else with the same error code coming up.
Any info much appreciated
Thanks.

I can't be certain as the pigpiss is a new concept to me (I mean, who even THOUGHT that up? ) but I do believe there is a known issue where the pumps pack in (somehow usually ay 120k miles.....almost as if they've been programmed from the factory to do so.....like the electric power steering modules that have been programmed to pack in after 1000,000 turns of the steering wheel BUT, who am "I" to suggest the manufacturers would resort to such dirty tactics

Might be worth getting the system interrogated & letting it know a "new" cat has been inserted (even though it "hasn't!" the system won't know until it has been "informed!"

Money, money, money

Thanks for the reply, mines done less than 60k, yep not good if that's what they are programmed to do.

[Newpicman]

I can't be certain as the pigpiss is a new concept to me (I mean, who even THOUGHT that up? )

The chemistry makes sense... Urea (a significant portion of mammalian urine) decomposes to ammonia in the heat of the exhaust and in the cat it turns harmful NOx compounds into harmless nitrogen and water...

But yes, the Adblue system as engineered by PSA may not be the best but then again, the offerings from others are not exactly wonderful either...

The problem stems from the tendency for Adblue to crystallise and these crystals can block things up.

It might be worth dosing the Adblue tank with a bottle of (e.g.) Wynns Crystal Clear and Protect but this may not help with a clogged one as yours may now be but it's worth a go.

It may also be a good preventative...

Your problem may be the urea injector being blocked with crystals... I understand it's not a big job to replace it.

Cheers Citrojim, will definitely try some of the Wynn's additive, did think it may have crystallized something with the ad blue running out and not warning me.

[Newpicman]

I wouldn't trust those codes - you need it on a better scanner.

An adblue fault won't give you a 'Electrical fault' warning so something else is going on. And if you haven't put any Adblue in it for over 25k miles, then almost certainly someone has been there before you and deleted the system....

When I 1st got the car, after a few months then the ad blue 1500 mile warning did come on, I then filled it up and it's not come on since. That's why originally I thought the level sensor may have packed in. Maybe like you say the electrical fault will be something completely different and only because it flashed up then this prompted me to do a check.
My Mrs does work at an MOT and servicing garage so will see if they can investigate deeper.
Thanks for taking the time to reply.

[RichardW]

Our 1.6 Grand does about 12k on a full tank of Adblue - 25k would be a long way, but it does use less in low speed driving. It has a feed back loop via the Nox sensor so if the tank was empty it would know via the Nox not getting reduced. Get some decent scan info off it, and go from there.

[Newpicman]

Our 1.6 Grand does about 12k on a full tank of Adblue - 25k would be a long way, but it does use less in low speed driving. It has a feed back loop via the Nox sensor so if the tank was empty it would know via the Nox not getting reduced. Get some decent scan info off it, and go from there.

Will do Richard, thanks for the info.

[Doo]

I wouldn't trust those codes - you need it on a better scanner.

An adblue fault won't give you a 'Electrical fault' warning so something else is going on. And if you haven't put any Adblue in it for over 25k miles, then almost certainly someone has been there before you and deleted the system....

I just read the codes & the set up looks "different" and whats with the dollar costings But what confused me was the cylinder 16 misfire!

Have you dropped a V16 in there Seriously though, this time of year is ripe for a bad battery to show it's face and that comes with added frustration of faults showing that may not actually be there! CanBus systems require absolute solid voltage, so a weak battery can flag up non faults. Your voltage issue could well be a battery, alternator or even a grotty earth sucking away much needed amps.

That is not to say there isn't a fault with your engine if it isn't drinking a cup of pee while running My own car (12 Lingo 1.6 8v) tells me there is some issue of additive, and yet I can't find the cause. I suspect it has been interfered with as it was a taxi at the start of it's working life. My Autel MaxiPro code reader is capable of programming many aspects of my car, but it's still a learning curve. I use it to interrogate & delete codes at the minute. I think I may need to secure a freebie running car & mess with it to see what happens. If I mess it up, it won't matter.

I digress, the chaps have suggested some good ideas and hopefully you get to the bottom of this issue. Meantime, I need to get a new battery for her indoors C4 as it's getting sluggish in the frosty mornings. Hasn't failed to start though

[Newpicman]

I wouldn't trust those codes - you need it on a better scanner.

An adblue fault won't give you a 'Electrical fault' warning so something else is going on. And if you haven't put any Adblue in it for over 25k miles, then almost certainly someone has been there before you and deleted the system....

I just read the codes & the set up looks "different" and whats with the dollar costings But what confused me was the cylinder 16 misfire!

Have you dropped a V16 in there Seriously though, this time of year is ripe for a bad battery to show it's face and that comes with added frustration of faults showing that may not actually be there! CanBus systems require absolute solid voltage, so a weak battery can flag up non faults. Your voltage issue could well be a battery, alternator or even a grotty earth sucking away much needed amps.

That is not to say there isn't a fault with your engine if it isn't drinking a cup of pee while running My own car (12 Lingo 1.6 8v) tells me there is some issue of additive, and yet I can't find the cause. I suspect it has been interfered with as it was a taxi at the start of it's working life. My Autel MaxiPro code reader is capable of programming many aspects of my car, but it's still a learning curve. I use it to interrogate & delete codes at the minute. I think I may need to secure a freebie running car & mess with it to see what happens. If I mess it up, it won't matter.

I digress, the chaps have suggested some good ideas and hopefully you get to the bottom of this issue. Meantime, I need to get a new battery for her indoors C4 as it's getting sluggish in the frosty mornings. Hasn't failed to start though

Thanks again Doo, there seems to be plenty of power in the battery although if I have it on stop/start it never activated but does flash up on the dash, I assume it's because there probably isn't enough in the battery to work or the other parameters aren't met. It hasn't worked for about 3 years. Cheers.

[Newpicman]

So had the car in the garage, connected to the obd reader and said it could be a sensor, new ad blue tank or possibly a nox sensor. On one of the other readers it said blockage detected and leakage detected but didn't know if this was because the ad blue had ran out. All codes reset, added a forte treatment for the ad blue and running it now. Not had any error messages come up but done another scan with my obd reader through the torque app and its showing the same fault as before. The ad blue cap looks like a vented one. The car was registered end of November 2005 so just over 8 years old.
What would be the best course of action now?
Just keep running it? Contact Citroen head office and see what they can do?
Most recent log below.
Thanks again.

Mode $06 report generated by Torque for Android
================================================

Vehicle VIN: Not present
Vehicle Manufacturer: Unknown
Vehicle Calibration ID: 9807589399

Test report:
------------------
MID:$21 TID:$81
- Catalyst Monitor Bank 1
Max: 655.34998 Min: 0.01
Test result value: 0.02
PASS
----
MID:$31 TID:$87
- EGR Monitor Bank 1
Max: 15% Min: -15%
Test result value: -0.35%
PASS
----
MID:$98 TID:$b1
- NOx/SCR Catalyst Monitor Bank 1
Max: 30 Min: 1
Test result value: 32.767
FAIL
----
MID:$98 TID:$b3
- NOx/SCR Catalyst Monitor Bank 1
Max: 75 Min: -50
Test result value: 16.5
PASS
----
MID:$b2 TID:$90
- Misfire Cylinder 16 Data
Max: 65,535 Min: 10
Test result value: 74
PASS
----
MID:$b2 TID:$91
- Misfire Cylinder 16 Data
Max: 1,000 Min: 0
Test result value: 12
PASS
----
MID:$e3 TID:$86
- Vehicle manufacturer defined
Max: 5.04% Min: 3.36%
Test result value: 3.93%
PASS
----


End of report.

[RichardW]

You need a diag tool that can read live data, and to watch the denox system data as it warms up.

Should see 4 bar pressure initially, and some level in the tank (not more than 6l as this is max it can read)
Should then go to pressurising when pressure should rise to 6 bar
Then it should go to injecting when pressure will drop to around 5.5 bar and then the nox should start to drop

Where it fails will give you a hint as to where the fault lies.

[Newpicman]

You need a diag tool that can read live data, and to watch the denox system data as it warms up.

Should see 4 bar pressure initially, and some level in the tank (not more than 6l as this is max it can read)
Should then go to pressurising when pressure should rise to 6 bar
Then it should go to injecting when pressure will drop to around 5.5 bar and then the nox should start to drop

Where it fails will give you a hint as to where the fault lies.

Cheers Richard, can you recommend a diag tool, would it have to be a standalone or would there be an app that does it?
Would this be adequate as it says live data?
https://amzn.eu/d/3QGHvYU