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

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

Post by GiveMeABreak »

Your car is specifically designed to run on Unleaded premium 95 and 98 RON fuels.

E10 is really designed for cars running 91 that are slightly newer. Putting in E10 in cars designed for premium 95 or 98 can cause poor running, knocking or pinging.

The cost of adding octane boosters and fuel cleaners to offset the differences may end up costing more than using the correct octane rated fuel, plus you may still get engine issues regardless, so I would stick to the correct rated fuel.
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Re: Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by zeeshanzaki »

I was able to read sensor data using generic obd2 but dont know if it is accurate or not. I can hear vaccume leak but not sure where it is coming from. If it is leaking from intake manifold then how to fix it. It also shows P0171 error when i scanned this morning.
While fixing rocker cover leak, rear platic cover oil breather pipe cracked and i have to use rtv to fix. I also applied rtv to other hose where i suspected could leaking too. Does rtv damage oxygen sensor?

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

Post by zeeshanzaki »

Hi Marc

I have checked voltage of both o2 sensor and they are not steady. Also read about short term fuel trim that also suggest MAF or catalyst. I had this issue before but it used to come up around 1000km but now it comes up every 100km after clearing code. Does cleaning MAF makes any difference?

Thanks

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

Post by GiveMeABreak »

P0171 isn't a specific fault code that comes up for this engine - but relates to the fuel mixture being too lean (not enough fuel).

But as I mentioned before, P0430 relates to the ageing of the pre-catalyst (rear cylinder bank) so you need to connect your scanner and go for a spin and check the data for the Downstream sensor; the voltage should remain steady as you can see on the blue line in the example in the video (not for the same car obviously). If the Downstream line or voltage starts fluctuating like the upstream one in Red, then more than likely, your CAT is at end of life and needs replacing. It's not done bad for an 18 year old car if on the original - but these things have a finite life.



You have separate issues going on here - a leak and a Cat problem.

If you had a MAF issue, then I would expect a code related to the air system that would indicate that. Although cleaning the MAF is recommended (with caution, using appropriate cleaner and not touching the sensor wire), this is not going to resolve the main issue that your CAT needs replacing.

How many miles has your car done?

The average life of a Catalytic converter is about 100,000 miles or 161,000 Km
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Re: Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by zeeshanzaki »

166000km.
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Re: Error P0430 - Catalyst System Efficiency below Thresold (Bank 2)

Post by GiveMeABreak »

So on the money there then, it’s about end of life and if the readings for the downstream are fluctuating then that would confirm it.
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