OBD codes / P0430 / Jeep Grand Cherokee
P0430 on a Jeep Grand Cherokee
Catalyst System Efficiency Below Threshold (Bank 2)
3.6L Pentastar V6 and 5.7L HEMI V8, WK2 (2011–2021) and later
What P0430 usually means on a Grand Cherokee
P0430 is the bank 2 counterpart to P0420 on the Grand Cherokee: the catalytic converter on the second cylinder bank has dropped below its efficiency threshold. It is normal for one bank to flag while the other stays fine, because the two converters age at slightly different rates. The usual answer on a high-mileage V6 or HEMI is simply a worn converter, though a small exhaust leak or a drifting O2 sensor on that bank can set it prematurely. Confirm which physical side is bank 2 on your engine before ordering parts.
Most likely causes on this model
- Worn bank 2 catalytic converter
The most common cause on aged trucks; the affected bank often trails the other by tens of thousands of miles.
- Exhaust leak on the bank 2 side
A leaking gasket or cracked pipe near that converter draws in air and fakes a low-efficiency reading.
- Lazy bank 2 upstream O2 sensor
A sluggish front sensor on that bank can misreport and trip the monitor.
- Upstream oil or coolant fouling
Anything that contaminates the exhaust stream on that bank accelerates converter decay.
What it costs on a Grand Cherokee
Because only one bank is involved, expect a converter and possibly a sensor for that side, usually a few hundred to over a thousand dollars installed. If both P0420 and P0430 are present, budget for two converters, which is where the bills climb. Emissions-state parts requirements again drive cost more than labor does.
Grand Cherokee owners also ask
Which side is bank 2 on my Grand Cherokee?
Bank 2 is the cylinder bank that does not contain cylinder 1, and the exact physical side depends on the engine, so confirm against a service diagram before buying a converter. Ordering for the wrong bank is a common and avoidable mistake.
Do I need to replace both converters if only P0430 is set?
No. If only the bank 2 monitor is failing, replace only that converter. Replacing a still-healthy bank 1 cat at the same time is a common upsell you can decline unless it too is reading low.
Year, engine and mileage change the answer. Get a diagnosis for your Grand Cherokee — it weighs these causes against your exact configuration and real complaint data.
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Based on widely reported patterns for this model; individual causes vary by year, engine and history. Generic P0430 behavior is covered on the main P0430 page. Confirm with a scan tool before buying parts.