Emissions · Diagnostic trouble code

P0430

Catalyst system efficiency below threshold (bank 2)

What it means

In plain terms

The bank 2 counterpart to P0420, on the other cylinder bank of a V engine.

What sets it

The trigger condition

The bank 2 post-catalyst O2 signal mirrors the upstream signal beyond the calibrated ratio over a complete monitor cycle.

Generic SAE definition. Manufacturers extend and sometimes override these, so the enhanced code on the vehicle in front of you may be narrower than what is written here.

Common causes

4 things that set P0430.

This is the list every other P0430 page will give you. Read it, then read the part underneath it.

What P0430 gives you
  • Degraded catalytic converter on bank 2
  • Failing downstream O2 sensor on that bank
  • Exhaust leak on the bank 2 side
  • Upstream engine fault damaging the converter
4 candidates · no ranking · your call
What AceDx gives you
One ranked call
Named specifically enough to order the part, with a confidence number and the evidence printed underneath.
1 call · evidence attached · you can overrule it
A frequency ranking is about every vehicle that ever threw P0430. You are working on one of them.
The actual problem

That list is not a diagnosis. It is a to-do list you did not ask for.

Every one of those 4 causes is now a decision somebody in the bay has to make, under a clock, on a car a customer wants back today.

We haven’t published a verdict for P0430 yet.

We could mock one up. We’re not going to. A fabricated example of our own product’s output is exactly the kind of thing this page is criticizing. Verdicts appear here as the pilot produces them on real vehicles, with the evidence they actually stood on.

Related codes

What often shows up beside it.

All diagnostic trouble codes →

Stop working P0430 from a list.

The pilot runs on your existing scan tool and your live repair orders. Bring us a car that's throwing this code.