What does it mean?
This diagnostic trouble code (DTC) is a generic powertrain code, meaning it applies to OBD-II equipped vehicles. Although generic, specific repair steps may vary by make/model.
Basically, it means the downstream oxygen sensor for catalytic converter bank 2 detects the converter isn’t operating as efficiently as it should (to specifications). It’s part of the vehicle’s emission system.
Symptoms
You likely won’t notice any driveability problems, though there may be symptoms such as rough/harsh cold idle.
Causes
A P0430 code can mean one or more of the following has occurred:
• The catalytic converter is no longer working properly
• An oxygen sensor isn’t reading (functioning) correctly
• There’s an exhaust leak
Possible Solutions
First inspect for exhaust leaks.
The next step is to measure the voltage at the bank 2 oxygen sensor. Actually, it would be a good idea to test each O2 oxygen sensor while you’re at it.
One thing to note is that many automobile manufacturers offer longer warranties on emission-related parts. So if you have a newer car but it’s out of its bumper-to-bumper warranty, there may still be a warranty covering this type of issue. Many manufacturers offer a five-year unlimited mileage warranty on these items. It’s worth checking.