P0430 on Chrysler: How to Diagnose & Fix
Catalyst System Efficiency Below Threshold (Bank 2)
1 Chrysler model · 1 documented issue · $400-$1,500 repair
P0430 on Chrysler by model: symptoms, diagnosis and fix
The 5.7L HEMI is notorious for exhaust manifold bolts breaking, especially on the passenger side. Thermal cycling causes bolts to become brittle and snap. Creates a ticking noise at cold startup that partially diminishes as engine warms but never fully goes away. Broken bolts can be extremely difficult to extract if snapped flush with the cylinder head.
Common Symptoms
- Ticking or exhaust leak noise at cold startup
- Noise diminishes as engine warms but doesn't fully disappear
- Visible exhaust soot around manifold flanges
- Failed emissions inspection
- Exhaust smell in engine bay
How to Fix
Extract broken bolts using ProMAXX drill template tool kit (PMXA200PROP) to safely extract without damaging cylinder head. Replace with upgraded Grade 8 double-ended studs and nuts instead of bolts. Apply anti-seize compound on new hardware. Consider Hooker Blackheart stainless replacement manifolds for a permanent upgrade on high-mileage vehicles.
Sources for this issue (1)
P0430 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0430 mean on a Chrysler?
P0430 stands for "Catalyst System Efficiency Below Threshold (Bank 2)." This code means the catalytic converter on Bank 2 (the side of the engine that does not contain cylinder #1) is not reducing emissions as effectively as it should. The computer compares the readings of the oxygen sensors before and after the converter; if the downstream sensor's signal starts mirroring the upstream one, it indicates the converter is no longer storing and processing oxygen properly. This usually points to a worn-out or damaged catalytic converter, but it can also be caused by faulty sensors or upstream engine problems that have poisoned the converter. The car will generally still run, but it will fail an emissions test. On Chrysler it is documented across 1 model: 300.
What are the most common causes of P0430?
The most common causes of P0430 are: Worn-out or failed catalytic converter (Bank 2), Faulty downstream (post-cat) oxygen sensor, Faulty upstream oxygen sensor giving bad data, Exhaust leak near the converter or sensors, Engine misfire or oil/coolant burning that damaged the catalyst, Running too rich or too lean over time, Aftermarket or non-compliant catalytic converter. The specific cause varies by vehicle.
How much does it cost to fix P0430 on a Chrysler?
Published repair estimates on Chrysler range from $400 to $1,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0430 on a different make?
View P0430 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.