P0430 Code: Bank 2 Location, Causes and Repair Cost

P0430 names the catalytic converter, the most expensive part in the exhaust, so the code reads like a bill before anyone has looked at the car. It comes from OBD-II, the self-check every car sold in the US since the 1996 model year runs, and it compares two oxygen sensors rather than looking at the converter.

On the Honda Pilot, which files most of the complaints, Honda's own bulletins point at the injectors and software, not the converter. So test before you buy.

What does a P0430 code mean?

A P0430 code means catalyst system efficiency below threshold on bank 2, and your car isn't measuring the converter directly. It's comparing two oxygen sensors, one before the converter and one after it.

A healthy converter stores oxygen and releases it, so the rear sensor should read steady while the front one swings. When the rear sensor starts to copy the front, the computer concludes the catalyst has stopped doing that, and it sets the code.

That's the whole test, and it's why the code's accurate but not specific. At least four kinds of fault can set a P0430 code, all by making the rear sensor mirror the front, and the code can't tell them apart.

Can you drive with a P0430 code?

Yes, in the sense that the car will run and the light stays steady rather than flashing. A steady light isn't the emergency a flashing one is, and what a flashing light means is worth knowing before you decide anything.

Even with a steady light, stop and have the car checked where it is if it loses power, smells of burning or overheats. Those signs need a shop now, not a planned visit.

Driving with a P0430 code is a bad idea anyway, even with a steady light, for two reasons that both end up on your bill:

• It can fail an emissions test. Honda warns its owners that with the light on, a car may fail a state or local emissions inspection.
• Every mile can be the damage. If the cause is fuel reaching the converter that should have burned in the cylinder, driving on it is what ruins the converter you're hoping not to buy.

Where is bank 2 on my engine?

Bank 2 is the side of the engine that doesn't contain cylinder 1. Its location moves from engine to engine, and on some it isn't the passenger side. On an inline four there's no bank 2 at all, so P0430 mostly shows up on engines with two banks, such as a V6 or a V8.

On the Pilot's 3.5L V6, cylinders 1, 2 and 3 sit in the rear bank against the firewall, so bank 2 is the front one, facing the radiator, which is the accessible side. Honda's bulletin lists P0430 as the “front bank” code.

Confirm this on your own engine before anyone orders you a part. The converter for one bank doesn't fit the other, and on a Pilot that mistake is a four-figure part sitting in a box.

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Will a P0430 code go away on its own?

The light can go out, but a converter still below the threshold sets the code again. The emissions rule lets the light go out after three drives in a row in which the catalyst monitor, the converter self-test, runs and passes. It lets the stored code be erased after 40 warm-ups without the fault.

That isn't the problem being fixed, because the next failed test lights it again. A cleaner won't restore a damaged catalyst, which our converter cleaner review covers.

What causes a P0430 code?

Four faults can set it: a tired converter, a lazy rear sensor, an exhaust leak ahead of the sensor, or fuel reaching the converter. The table gives the clue for each, the test that names the part, and what not to buy before that test.

Only the first of the four is the part the code is named for. What the converter actually does explains the chemistry behind the two-sensor comparison.

How do you fix a P0430 code?

Free checks first, then the shop's tests in order, and the converter last. The first three steps cost nothing but time.

The shop's five checks follow them, and a quote should follow the same order. A quote that starts at the converter skips the cheaper answers.

What you can check yourself, before anyone charges you

To fix a P0430 code, start with the 3 steps below, and you can work through all three before anyone charges you:

1. Read the full code list, not just P0430. A cylinder balance or misfire code sitting next to it changes the whole diagnosis. Reading the codes yourself takes a scan tool and a few minutes.
2. Check whether the vehicle is covered. A warranty extension can make this somebody else's bill. Run your VIN through our VIN decoder for recalls, and on a Pilot, Odyssey or Ridgeline ask a dealer about Honda's injector extension.
3. Ask to see both oxygen sensors on live data, warm. This is the test the code itself runs: the rear sensor should stay comparatively flat while the front one moves, and a rear sensor copying the front is what sets the code.

Many newer cars use a wideband front sensor, a type that reads smoothly instead of swinging, so the shop reads the comparison on its scan tool. A rear sensor stuck at one voltage that never responds points to the sensor or its wiring.

If the dealer finds no coverage on your VIN, check the converter's federal 8 years or 80,000 miles before paying for one. If the scan shows a cylinder balance or misfire code beside P0430, show it to the shop: that code names the fuel side, the shop's fourth step below.

What the shop does, and in what order

The rest is shop work. A shop fixing a P0430 code works through these checks in order, and the order is worth knowing even though you aren't doing it, because it's what a quote should follow:

• Freeze frame first. The scan tool stores the conditions the code set under. Speed, load and coolant temperature narrow the cause before anything is unbolted.
• Smoke or pressure test the exhaust ahead of the sensor. This is the cheapest fault on the list to find and to weld shut, and the test finds it without removing anything.
• Swap or bench test the downstream sensor. A lazy sensor produces the same comparison a dead converter does.
• Read fuel trim and injector balance. Fuel trim is the computer's fuel correction for each bank. This is where the Pilot's answer lives. Trims that differ between the two banks, or a cylinder balance code beside the catalyst code, name the fuel side. Carmakers don't publish a threshold for it.
• Only then the converter. And with whatever killed it fixed first, or the same code returns.

A quote that goes straight to step five without the four above it skips the cheaper checks. Ask which of the four were done, and what each one found.

What does a P0430 repair cost?

Often nothing, if a warranty pays: Honda's injector extension on some V6 models, or the converter's federal 8 years or 80,000 miles. Check both by VIN before you pay for a part.

Outside them, the rear oxygen sensor is the small end of the bill, and a shop can bench test the old one or swap in a known good one before you buy. Honda sells the Pilot's injectors as a set, not one at a time, so a set is the price to compare.

The converter is the expensive end. On a 2022 Ford F-150 5.0, a federal converter (built to EPA rules, not California's) for bank 2, the left side, runs $644–$804 at an independent shop, parts and labor, when no recall covers it.

On the Pilot, the bank 2 converter comes in one piece with the exhaust manifold, which makes it cost more than a plain converter. Cheap listings can be universal weld-in units rather than a part that bolts to this engine, and what a converter costs to replace covers that split.

Which codes come with P0430?

A second code beside P0430 can name the cause before anyone looks at the converter. Carmaker bulletins pair it with four kinds of code, and each pairing tells you something.

P0420 beside it means both banks report at once, so look for one cause that reaches both, covered below. A misfire code points at fuel or ignition first.

A cylinder balance code, P219A or P219B, belongs with the injector fault in the Pilot section. P0174 means bank 2 is running lean, which one carmaker warns can damage the converter.

A V6 with two converters

What if P0420 and P0430 appear together?

When both banks report the same fault, look upstream first. Something feeding both converters, such as the fuel mixture, is worth testing before anyone prices two of them.

Honda's own bulletins are titled for both codes together, which tells you the manufacturer expects to see the pair. Fuel, oil consumption, a coolant leak into the combustion chambers past a failed head gasket, and a software fault all reach both banks, and a single failed converter can't.

Both codes can also be a false alarm. On some GM V8s, a converter that has just been fitted, or a battery disconnected, can set both before the converter has broken in, and the fix is to clear the codes and drive the cycle.

On some Ford trucks the light can come from the engine computer itself. Ask a Ford dealer about a software update before you buy a converter.

Our P0420 article works through the bank 1 version of this. It also follows the chain of cheaper causes that sit behind it.

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Why does the Honda Pilot get P0430 so often?

Because the Pilot's P0430 is mostly an injector fault, not a converter one, and the owners writing in say so. About seven in ten Pilot owners reporting P0430 mention the fuel injectors.

Honda files more P0430 complaints than any other make, and the Pilot carries most of them. Complaints count the people who wrote in, not the failure rate, so read that as a clue rather than a verdict.

Some add P219B or P219A, the bank 2 and bank 1 cylinder balance codes, or a misfire code. Others mention a recall or a warranty, so owners were already being told this was a known fault.

A bank 2 cylinder balance code next to a bank 2 converter code means one side of the engine runs badly and sends unburned fuel to its converter. The converter is downstream of the problem.

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Is your Pilot still covered by Honda?

Possibly, and this is the first thing to check rather than the last. American Honda extended the warranty on the fuel injectors in certain Pilots, Ridgelines and Odysseys to ten years from the original date of purchase or 150,000 miles, whichever comes first.

A service bulletin is the written instruction a manufacturer sends its own dealers: what the fault is, what to replace, and who pays for it. It's not a recall, and though Honda says it mails owners of affected vehicles, a second owner may not see that letter.

The extension covers certain Pilots, Odysseys and Ridgelines, and Honda's bulletins are titled for the codes themselves. A dealer looking at the title alone can see it covers what your scanner is showing.

Honda names two causes. Debris from the high-pressure pump or from machining wears or clogs the injectors, and software can misread the sensors as a worn converter, so the code can come from a misreading, not a failed part.

With P0420 or P0430 alone, a cylinder air-fuel test decides whether the injectors are replaced. With a misfire or cylinder balance code beside it, they're replaced outright.

The clock is the problem now. Ten years from purchase means the earliest Pilots are at or past the limit, while the newest covered ones, 2019 models, have until 2028 or later, depending on when they were bought.

Coverage is decided per vehicle by VIN, so ask a Honda dealer to look yours up before you pay for anything. If the extension has run out, check whether the converter's own federal cover below still applies.

Whatever the badge, the converter has its own federal cover: federal law gives it a warranty of 8 years or 80,000 miles, whichever comes first. Check both numbers before paying for a converter: inside them, the federal warranty can put a failed converter on the carmaker's bill.

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Common questions

Asked most often

Is the second character in P0430 a zero or a letter?

A zero, because only the first character is a letter and the four after it are digits. On a scan tool display a zero and a capital O look almost identical, so typing PO430 into a parts catalog returns nothing and makes a real code look as though it doesn't exist.

Is P0430 upstream or downstream?

Neither sensor sets it on its own, because the code is the comparison between them, the upstream sensor ahead of the converter and the downstream one behind it. In practice a downstream sensor reading slowly is the cheapest thing that produces the same comparison, which is why it's worth ruling out before the converter.

Why does P0430 come back after a new converter?

Because whatever killed the first converter is still there. Replacing the converter alone buys the same code again, and GM notes a converter only just replaced can still set a false P0420 and P0430 until the codes are cleared and the drive cycle is run.

Prices are ranges compiled from September to November 2026 for the US market and vary by region, engine and shop rate. Prices from $10 up are rounded to the nearest dollar, so $14.13 reads as $14 and $14.52 as $15. Below $10 they're exact. This article is general information, not advice about your specific vehicle. See the disclaimer.