Mine is a 2013 2.0L petrol with a persistent P0420 code that hasn't gone away after running through multiple cleaner products via fuel tank. I haven't found anything with steps for how to remove the cat. Wondering if anyone has any pointers. Did find a Ford Escape with same engine on YouTube and looked to me a LOT of parts to remove to get at the exhaust section with the cat.

EDIT FOR CLARITY: to be clear, I'd never aim to just remove but rather remove and replace or potentially remove/clean/refit.
Asking for help with removal and replacement "how-to's"

Cheers,
Scott

Last edited by LRD414 on 14th Mar 2024 9:15 pm. Edited 2 times in total

A P0420 code is saying that the cat isn't functioning correctly. If you remove the cat (it might be illegal in your area anyway), you'll still get the P0420 code, because a missing cat can't function correctly.

I'd change the post cat sensor first, just in case it's a false code.
After which you'll probably have no choice by to buy a new cat. Hyundai Ioniq 5 Ultimate. The family car.
2009 Rimini Red SE TD4. Gone.
2006 Tonga Green i6 HSE. Gone.
Audi A5 convertible, my daily driver.
1972 Hillman Avenger GT, the project.

Probably should have made it clear that I'd never aim to just remove but rather remove and replace or potentially remove/clean/refit.

And I'm already considering sensor replacement as a first step, although I would have guess a different fault code if the sensor was faulty, ie one related to "sensor out of range" or something like that.
Does the down stream O2 sensor commonly fail ?

A O2 sensor can fail in a number of ways, but often just go slight out of range. This can result in a a false P0420 code, or sometimes an out of range code.
I'm assuming there's no air leaks in the exhaust system, or there are no engine faults present, like a leaking injector or failing spark plugs.

All O2 sensors lose sensitivity as they age, some suggest they are replaced at 100k miles or so.

Do you have suitable diagnostic equipment to monitor or graph the O2 sensors? If so then it's worth comparing the outputs between the upstream and downstream sensors, to see if anything looks miles off. Hyundai Ioniq 5 Ultimate. The family car.
2009 Rimini Red SE TD4. Gone.
2006 Tonga Green i6 HSE. Gone.
Audi A5 convertible, my daily driver.
1972 Hillman Avenger GT, the project.

I've got a Gap iiD BT that's registered to my D4 but I can read and chart live values and read/clear faults on the F2. If you've got any idea of typical O2 sensor readings that would be very helpful.

New factory O2 sensors are expensive in Australia so I need to look into alternative suppliers and also I'll look to see what live values are running before replacing.

No other fault codes and quite new spark plugs and no evidence of exhaust leaks. Did have an evap system high purge code about 9 months ago that was fixed by replacement of an evap system valve. Only the P0420 returns.

When graphing O2 sensors, you should see them pulsing up and down in a regular sinewave, a bit like a heart monitor does. They should peak up to about 1 Volt, before falling to about 0.1 Volt, so giving an average of about 0.5 Volt over a long period of time.

If the pulsing isn't regular, or doesn't peak out at almost 1 Volt, then it suggests that the output of that O2 is suspect.

Another thing to check would be the fuel trims. Short term trims alter by as much as + or - 5, but long term trims should remain close to zero on a well running engine, however up to + or - 5 is acceptable. Hyundai Ioniq 5 Ultimate. The family car.
2009 Rimini Red SE TD4. Gone.
2006 Tonga Green i6 HSE. Gone.
Audi A5 convertible, my daily driver.
1972 Hillman Avenger GT, the project.

I replaced my O2 sensor after putting on a cheap sensor with a Bosch one from a good company (Parts In Motion) off EBay. So long as you go for a good make any 5 wire wideband one should do

Logged sensor 2 on a 3 minute drive after engine warmed up. Peaked at ~0.82v and down to 0.1v. Generally the high value was 0.77 to 0.79. Showed a regular sinewave style pattern but stayed down at low value a couple of times i was waiting at a stop sign. Held at higher range (0.82 - 0.78v) with open throttle up a hill.

Couldn't find a sensor 1 voltage in live values

Short Term Fuel Trim of -15% to +15% but mostly -10 to +10 over a short drive
Long Term Fuel Trim drop from zero to -5% over a short drive

Short term trims of + or - 15 suggested there's a mixture control issue that the ECM is trying to compensate for. Have you checked the intake trunking for air leaks. Hyundai Ioniq 5 Ultimate. The family car.
2009 Rimini Red SE TD4. Gone.
2006 Tonga Green i6 HSE. Gone.
Audi A5 convertible, my daily driver.
1972 Hillman Avenger GT, the project.

Not sure if I am going off on a tangent, but I only stick 98 in the car other than the few remote outback places in Western Australia, but at least could average fuel to roughly 95 with mixing with 50 litres of 98 on the roof (managed to avoid various people sniffing it. Aviation fuel in central Australia for cars to avoid sniffing issues).

Previous car had issues with 91 even though it could take 91. Stopped using 91 as advised by my mechanic decades ago. Never had an issue with 98. Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

I'm surprised 91 is available in Australia, considering lots of vehicles come from Japan, where vehicle's are designed for fuels that have a rating of 95 or more.
In the uk standard pump petrol is E10 (10% ethanol) which has a 95 rating. There are also super grades available, which have up to a 99 rating. Hyundai Ioniq 5 Ultimate. The family car.
2009 Rimini Red SE TD4. Gone.
2006 Tonga Green i6 HSE. Gone.
Audi A5 convertible, my daily driver.
1972 Hillman Avenger GT, the project.

Well to bring things back on topic and close out thread ... I've given up, the lowest of the three bolts to the exhaust manifold is beyond my capability

Nodge68 wrote:

I'm surprised 91 is available in Australia, considering lots of vehicles come from Japan, where vehicle's are designed for fuels that have a rating of 95 or more.
In the uk standard pump petrol is E10 (10% ethanol) which has a 95 rating. There are also super grades available, which have up to a 99 rating.