Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

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zeeshanzaki
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Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by zeeshanzaki »

I am getting this error every now and then. I use generic OBD2 reader to clear the fault. It disappear for 1000km or so and then come back again. Its been happening since two years and I dont see any issue in driving, but just want to know what could be the cause of the issue. Most of the time this error appear when starting the car in the morning.
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Paul-R
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Re: Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by Paul-R »

It might help to give some more details such as engine type, year and model. If you post up your VIN (it will be masked by the forum software) that will tell everything to those who can understand these things.
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Re: Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by GiveMeABreak »

I've got your VIN from last time. ( C5 5 DOOR SALOON 3.0i V6 24v 210 (ES9J4S) Auto gearbox 4)

P0430: Aging of the pre-catalyst (rear cylinder bank)

The above fault is associated with a failing CAT. Check all the seals around the exhaust manifold for any leaks - but if it looks ok then undertake the following test:

With the engine running at operating temperature, check the readings of the downstream O2 sensor with a multimeter. There should be a steady voltage of about 0.45V if the CAT is working correctly - but if the readings fluctuate up and down from 0.1V to 0.9V it would indicate that the CAT is at the end of its service life and needs replacing.

I don't have a lot of data on the early C5, but this is a likely suspect - clearing the fault will not make a difference, as the issue is still there. What sort of mileage has it done?
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Re: Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by zeeshanzaki »

Hi Marc

Can you please tell me where downstream o2 sensor located. How do i check voltage when it is already connected.
Also one of the o2 sensor behind the engine is very dirty due oil leak from valve cover. Please see the attached photo
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Screenshot_20181027-121159_Gallery.jpg
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Re: Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by GiveMeABreak »

Ok, so here are all the components of the Bosch Injection system for you.

The Downstream O2 sensors have 4 wires. Here are the 4 Sensors Up & Down Front and Up & Down Rear. I think the one reporting the error is 1354. On this sensor, here are the wire codes:
1351C: Lambda sensor heating power supply
125: Control Heating Lambda Sensor D Downstream Catalytic Converter
1305: Signal from Lambda Sensor D (-) Downstream of the Catalytic Converter
1304: Signal from Lambda Sensor D (+) Downstream of the Catalytic Converter

Zeesh O2 Circuit.PNG
1352: Front Downstream Oxygen Sensor
1353: Front Upstream Oxygen Sensor
1354: Rear Downstream Oxygen Sensor
1355: Rear Upstream Oxygen Sensor

Here are the components and 21 is the downstream sensors s0 you can see the location:
C5 MK I O2 Semsors A.PNG
C5 MK I 30 Bosch Parts.PNG
RefDescriptionRefDescription
(1) Fuel consumption data.(19) Variable timing electrovalve (x2)
(2) Injection ignition test warning lamp.(20) Upstream oxygen sensor (x2)
(3) Tachometer.(21) Downstream oxygen sensor (x2)
(4) Air conditioning ECU (according to equipment(22) Engine coolant temperature sensor.
(5) Multifunction screen.(23) Knock sensor (x2)
(6) Built-in systems interface.(24) Power steering pressure sensor.
(7) Transponder.(25) Integral pressure sensor.
(8) Automatic gearbox ECU (according to equipment(26) Accelerator pedal position sensor.
(9) Pump, fuel filter and pressure regulator assembly (except grande exportation)(27) Air temperature sensor.
(10) Battery.(28) Diagnostic connector.
(11) Pressostat.(29) Injection multifunction double relay.
(12) Engine speed sensor.(30) Ignition injection control unit.
(13) The camshaft position sensor (x2)(31) Pulsation damper.
(14) Motorised throttle housing.(32) Spark plugs (x6)
(15) Canister discharge electrovalve.(33) Fuel tank.
(16) Electric cooling fan unit.(34) Canister reservoir.
(17) Pencil type sparking plug (x6)(35) Pressure relief valve.
(18) Petrol injector (x6)(36) Exhaust system.

C5 MK I O2 Sensors B.PNG
RefDesignationReferenceTightening torque
1Upstream Oxygen Sensor (Rear)A 258 040 2325 ± 1 daNm
2Downstream Oxygen Sensor (Rear)A 258 040 2325 ± 1 daNm
3Downstream Oxygen Sensor (Front)A 258 040 2325 ± 1 daNm
4Upstream Oxygen Sensor (Front)A 258 040 2325 ± 1 daNm
5Pre-Catalyst (Rear)TR PSA K 1603,3 ± 0,5 daNm
6Pre-Catalyst (Front)TR PSA K 1593,3 ± 0,5 daNm
7Front Flexible Pipe - -
8Catalytic ConverterTR PSA K 175 PSA 41493,3 ± 0,5 daNm
9Rear SilencerPSA 4143 -
10Collars - 2,5 ± 0,3 daNm

Your best bet is to use Lexia on it which will give you the live data on the O2 sensors. This should easily tell you the voltage - this video demonstrates (non-Citroen), but you get the idea.



If you don't have a Lexia, then either another diagnostic tool capable of providing live data or you'll have to backprobe the wires, which can be awkward - but is explained here on a different vehicle:

https://axleaddict.com/auto-repair/How- ... gen-Sensor

Good Luck
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Re: Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by zeeshanzaki »

Hi Marc

Thank you so much for sharing detail information, much appreciated. I will see if I can source lexia or will try other solution you provided.
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Re: Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by zeeshanzaki »

Hi Marc
I noticed there is oil leak around exhaust, don't know if it is from previous rocker cover oil leak or it is coming from exhaust. Please see the attached image for exact location with red arrow. Could this be causing this error??


GiveMeABreak wrote:
26 Oct 2018, 09:15
I've got your VIN from last time. ( C5 5 DOOR SALOON 3.0i V6 24v 210 (ES9J4S) Auto gearbox 4)

P0430: Aging of the pre-catalyst (rear cylinder bank)

The above fault is associated with a failing CAT. Check all the seals around the exhaust manifold for any leaks - but if it looks ok then undertake the following test:

With the engine running at operating temperature, check the readings of the downstream O2 sensor with a multimeter. There should be a steady voltage of about 0.45V if the CAT is working correctly - but if the readings fluctuate up and down from 0.1V to 0.9V it would indicate that the CAT is at the end of its service life and needs replacing.

I don't have a lot of data on the early C5, but this is a likely suspect - clearing the fault will not make a difference, as the issue is still there. What sort of mileage has it done?
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OilLeakAroundExhaust.jpg
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Re: Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by zeeshanzaki »

Found loose hose connected to plenum. No more anti pollution fault after reconnecting properly.

Thank you.
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Re: Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by GiveMeABreak »

Great, well done!
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Re: Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by zeeshanzaki »

Error came back again after driving few days. Car is runs fine with no issue at all.
I dont have lexia so can't test O2 sensor. If the cat need to be changed, how many are there and which one need to be change.
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Re: Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by GiveMeABreak »

Here's your catalytic converter, item 17: Click the picture to zoom.
Zees Catalytic B.PNG
UK prices form Citroen - but you will hopefully find a supplier of these down under.
Part numbers:
Original: 170693 - £371.03
Alternative: 1612915180 - £739.70
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Re: Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by zeeshanzaki »

Thanks Marc.
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Re: Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by RichardW »

Whilst 17 is the main CAT, Marc, I think this fault is pointing at something different... You will note it says specifically 'rear bank' - and on the diagram there is no sensor D/S of the main cat... If you look back at the picture you posted at the end of October, you can see the sensors listed:
GiveMeABreak wrote:
27 Oct 2018, 10:57


C5 cats.PNG
RefDesignationReferenceTightening torque
1Upstream Oxygen Sensor (Rear)A 258 040 2325 ± 1 daNm
2Downstream Oxygen Sensor (Rear)A 258 040 2325 ± 1 daNm
3Downstream Oxygen Sensor (Front)A 258 040 2325 ± 1 daNm
4Upstream Oxygen Sensor (Front)A 258 040 2325 ± 1 daNm
5Pre-Catalyst (Rear)TR PSA K 1603,3 ± 0,5 daNm
6Pre-Catalyst (Front)TR PSA K 1593,3 ± 0,5 daNm
7Front Flexible Pipe - -
8Catalytic ConverterTR PSA K 175 PSA 41493,3 ± 0,5 daNm
9Rear SilencerPSA 4143 -
10Collars - 2,5 ± 0,3 daNm
i.e. Item 2 is the rear bank D/S sensor and item 5 is the rear bank pre-cat. So the fault code is pointing a fault here, rather than the main cat (about which the ECU knows nothing). I would be looking at the live data for the rear bank D/S sensor first to see what it is doing, esp since it is covered in oil! The rear bank cat is an eye watering £823, the O2 sensor 'just' £192 (although this should be available cheaper aftermarket).
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Re: Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by GiveMeABreak »

Thanks for the reminder Richard - I just wanted to try and answer the CAT specific replacement question. Very pricey parts on the 3.0 V6 though :)
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Re: Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by zeeshanzaki »

I found two error codes when i tried to clear codes. Now it is repprting error in bank1 also. I think this might be using ethanol base fuel. I started using 98 octane fuel and will see how it goes.