- Vehicles
- Cars
P0430
P0430 (generic OBD-II): catalyst efficiency below threshold, bank 2
Risk level
Medium
Proceed carefully and stop if the check is unclear.
Urgency
Medium
Quick answer
The bank 2 catalyst monitor (the side of the engine without cylinder 1) returned a low result. It is not an order to replace the converter. Check whether the light flashes, read all codes and save the freeze frame.
Safety first
Stop and check this first
- Replacing the bank 2 converter without checking sensors, mixture, misfire and bulletins can leave the same code.
Safe checks you can perform
- Light state and fuel cap
- Codes that come with P0430
- Monitor result and bank 2 sensor signals
Leave these tasks to a qualified professional
- Do not attempt this professional task: Bulletin search by VIN before replacing parts
- Do not attempt this professional task: Live bank 2 sensor data and fuel trims
- Do not attempt this professional task: Monitor completed after the repair
What a technician must be able to justify
Technician visit
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Bulletin search by VIN before replacing parts
What they doThe workshop searches bulletins for your model and engine with P0430; if one matches, it applies that procedure.
They must show youthe result of the bulletin search by VIN.
In writingthe bulletin number applied or that none exists.
Live bank 2 sensor data and fuel trims
What they doThe technician watches the bank 2 upstream and downstream sensors and that bank's fuel trims live, and rules out misfire and mixture faults.
They must show youthe graph of both sensors, the fuel trims and the monitor value against the limit.
In writingwhich other faults were ruled out and, if the converter is replaced, the reason and part number.
Monitor completed after the repair
What they doAfter the repair, the technician lets the catalyst monitor complete again and confirms P0430 does not return.
They must show youthe catalyst monitor status as complete.
In writingthe date and mileage at which it completed with no code.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Follow these steps
Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
Light state and fuel cap
- Who:
- you, with the car parked and the engine off for the cap.
- How:
- note whether the light flashes while driving and check the fuel cap is fitted and tight.
- Result that matters:
- whether the light flashes and whether the cap was loose.
- If it flashes:
- there is an active misfire, more urgent than P0430; stop somewhere safe and follow the manual.
- If it is steady and the cap is fine:
- the next step is reading the codes; a loose cap does not explain P0430 on its own.
- Evidence to keep:
- a photo of the cluster and a note of the cap's state.
Evidence: Nissan USA malfunction indicator light guide · Honda 2020 HR-V Owner's Guide - Dashboard details (malfunction indicator lamp)
Codes that come with P0430
- Who:
- you, with a generic OBD-II reader.
- How:
- read confirmed and pending codes and save the freeze frame before clearing anything.
- Result that matters:
- whether P0420, oxygen sensor, mixture or misfire codes also appear.
- If there are sensor, misfire or mixture codes:
- according to Ford those faults disable the monitor; the workshop must fix them before judging the converter.
- If P0430 is alone or with P0420:
- ask the workshop to check bulletins by VIN before quoting for converters.
- Evidence to keep:
- a photo of the code list and the freeze frame.
Use the reader with the car stopped and do not clear: the freeze frame would be lost.
Evidence: Ford 2020-2023 gasoline OBD system operation · Ford TSB 24-2184 F-150 2.7L P0420/P0430
Monitor result and bank 2 sensor signals
- Who:
- the workshop, with diagnostic equipment.
- How:
- read the bank 2 catalyst monitor result (mode 6 if the car offers it) and the signal of both sensors on that bank.
- Result that matters:
- the measured value against the calibration limit and whether the sensors respond.
- If the sensors respond well and the value is still out of limit:
- the bank 2 converter becomes the stronger suspect.
- If a sensor responds poorly:
- fix the sensor before condemning the converter.
- Evidence to keep:
- a capture of the monitor result and both signals.
The exhaust burns: do not get under the car or remove anything.
Evidence: Ford 2020-2023 gasoline OBD system operation
Still not solved
If the error persists, stop here. See what the technician must do and show you.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- Vehicles
- Brand
- OBD-II genérico
- Product type
- Cars
Known code variants
- P0430
- P0430 catalizador banco 2
- P0430 catalytic converter bank 2
- P0430 OBD2
What it means
P0430 is the generic code for catalyst efficiency below threshold on bank 2, which only exists on V engines or engines with two exhaust paths. In Ford's OBD summary the monitor makes no call until the oxygen sensor tests complete, and it is disabled by sensor, misfire, mixture, temperature or EVAP faults. Ford also published a bulletin where P0420 and P0430 were due to calibration sensitivity and were fixed with a stabilisation drive cycle.
Warnings and stop conditions
- Mediumeditorial warning
Replacing the bank 2 converter without checking sensors, mixture, misfire and bulletins can leave the same code.
Evidence: Ford 2020-2023 gasoline OBD system operation · Ford TSB 24-2184 F-150 2.7L P0420/P0430
Symptoms and causes
Probable causes · in order
- Bank 2 converter with low capacityPossible
The converter stores less oxygen than the calibration requires. Accept it only when the bank 2 sensors and other systems are verified.
Evidence: Ford 2020-2023 gasoline OBD system operation
- Bank 2 oxygen sensorsPossible
The monitor compares the sensors before and after the converter. A slow sensor or circuit fault gives the same result with a healthy converter.
Evidence: Ford 2020-2023 gasoline OBD system operation
- Another engine faultPossible
Misfire, mixture or EVAP faults disable or distort the monitor. Suspect it when P0430 comes with other codes.
Evidence: Ford 2020-2023 gasoline OBD system operation
- Manufacturer calibrationLess common
On the 2018 to 2020 Ford F-150 2.7L, Ford attributes P0420 and P0430 to calibration sensitivity and applies a stabilisation drive cycle. It only applies if the bulletin matches.
Evidence: Ford TSB 24-2184 F-150 2.7L P0420/P0430
Virtual technician
Does P0430 still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
Nissan USA malfunction indicator light guide
Nissan USA · official_doc
- 2
Ford 2020-2023 gasoline OBD system operation
Ford Motor Company · 2023 · manual
- 3
Ford TSB 24-2184 F-150 2.7L P0420/P0430
Ford Motor Company · 2024 · service_bulletin
- 4
California Air Resources Board · 2006 · official_doc
- 5
Honda 2020 HR-V Owner's Guide - Dashboard details (malfunction indicator lamp)
American Honda Motor Co. · 2020 · manual
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