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I have a little issue with the Code P0430. Obviously, I hope it doesn't mean I have to change the cat...
For some context: I got this 2005 XJ8L (128k miles) that seemed like it was sitting somewhere for quite a bit, due to spiderwebs and wasp nests all over the engine. Previous owners didn't take the best care of it. I fixed multiple leaks it had, from changing the valley hose to replacing the radiator, and now it drives without overheating.
One of the issues we saw, was an O2 sensor code for upstream bank 2 (P1647). We replaced that O2 sensor with no change on the code, then swapped banks. Still no fix. We then noticed that the green cable to the connector to the O2 sensor was loose/worn. So we rewired the connector and got appropriate signal in all pins. Seeing as the connector was the issue, we decided to keep the previous O2 sensor sensor that came with the car and put it in bank 1.
Forward to a few days ago, Code P0430. Car runs fine in my opinion, but the computer thinks otherwise.
Here's a few charts of the live data on the sensors running at idle.
My guess is a potential air leak? I am not sure if the fluctuation in Bank2 downstream suggests a busted Cat. Any ideas on what I could do to diagnose would be much appreciate it. I really like the car and I want it to last as long as possible.
Airleaks first possible place just for inspection is your airfilterbox, airfilter and duct to throttlebody. And clean the maf with maf spray cleaner.
we had had an xjr engine duct with an open hole on the bottom of the duct wich had to be fixed, possibly grinding on the aux belt just below.
this was possibly the reason of a wrecked Catalyser
I had the same code some years ago after buying my car: yellow light on the dashboard on, code P0430, delete it, drive for some days, yellow light on again, P0430 code, etc.
The car always drove nicely.
In the end, I had to replace the cat (everything else was new by then). But when I did that, the reason for the fault became obvious: the cat was empty! I don't know how the car passed all the emission tests...
you can go with OEM, expensive... or ebay aftermarket starting around 200 USD, or look for a used Ford Catalytic converter, which has same part number in the middle, cut open the cat container and replace the core, weld together... that's what I did, got a used Ford cat at the junkyard, 250 USD including labor, works like new.
5E212 is the part number of the core unit.
I have a little issue with the Code P0430. Obviously, I hope it doesn't mean I have to change the cat...
--snip--
My guess is a potential air leak? I am not sure if the fluctuation in Bank2 downstream suggests a busted Cat. Any ideas on what I could do to diagnose would be much appreciate it. I really like the car and I want it to last as long as possible.
Thanks in advance!
Hi mmoreno,
I see you have changed the upstream sensors and got them working ok. If you only have P0430, could you swap the downstream sensors between the left and right cats and see if you then get a P0420? My car would get both P0420 and P0430 errors after about a week of driving. My country does not have emissions testing, so I purchased right-angle spacers for the downstream sensors. This puts the sensor a greater distance from the exhaust stream, and since then, no errors. The downstream sensors don't affect the car's running parameters, but are a check for the 'health' of the cat. Sensors are expensive here, but may be cheaper in your country.
Hi mmoreno,
I see you have changed the upstream sensors and got them working ok. If you only have P0430, could you swap the downstream sensors between the left and right cats and see if you then get a P0420? My car would get both P0420 and P0430 errors after about a week of driving. My country does not have emissions testing, so I purchased right-angle spacers for the downstream sensors. This puts the sensor a greater distance from the exhaust stream, and since then, no errors. The downstream sensors don't affect the car's running parameters, but are a check for the 'health' of the cat. Sensors are expensive here, but may be cheaper in your country.
Pete M
Yes, we swapped downstream sensors and the issue stayed in bank 2. Also, I tapped bank 2 Cat and it rattled a little bit. For now I just have a scanner handy so I can clear it and make sure that's the code. Will probably end up getting a new aftermarket cat.
The downstream sensors don't affect the car's running parameters, but are a check for the 'health' of the cat. Sensors are expensive here, but may be cheaper in your country.
Pete M
Agree with Pete on that statement, only upstream sensor affect performance and fuel economy.
I ordered my sensors at Aliexpress, upstream 27 USD each, downstream 20 USD each , including shipping. A little for import duty in my location on top, 5%. Running all as should since 4 months and 10.000 km, longterm will show if the quality is right.
Well, the code does seem to be as accurate as it gets. Inside of that cat looked like it was ready for smoking aome ribs.
One of the honeycomb was absolutely in shambles. On first drive back home it felt noticeably better when accelerating and held speed for longer when cruising. We used an Ebay direct fit part which, well, fitted perfectly. Only time will tell if it lasts enough. Thanks everyone!
Code P0430
