What P0430 Means on Your 2022 Lexus IS
The 2022 Lexus IS received a significant refresh. The IS 350 features the 3.5L V6 (2GR-FKS) with 311 horsepower, while the IS 300 RWD uses a 2.0L turbocharged four-cylinder (241 hp), and the IS 300 AWD offers a 3.5L V6 (260 hp). The high-performance IS 500 introduced the 5.0L V8 (2UR-GSE) with 472 horsepower. A P0430 code indicates the ECM has detected reduced Bank 2 catalytic converter efficiency.
The IS is built for performance, and the V6 and V8 engines produce substantial exhaust heat. Let's look at the causes and your repair options.
Common Symptoms
- Steady check engine light
- Slight fuel economy decrease
- Possible sulfur smell from exhaust
- No major performance changes
- Emissions test failure
Top Causes of P0430 on the 2022 Lexus IS
- Faulty Air-Fuel Ratio/O2 Sensor (37% likelihood) — On a vehicle this new, a sensor issue is the most likely cause. The downstream sensor on Bank 2 may have a manufacturing defect or premature failure.
- Catalytic Converter Issue (30% likelihood) — The 3.5L V6 and especially the 5.0L V8 produce significant heat. Enthusiastic driving can accelerate converter wear even on newer vehicles.
- Exhaust System Leak (20% likelihood) — A gasket failure, flex pipe issue, or loose connection can introduce air into the exhaust stream, confusing the O2 sensor.
- Software Calibration Issue (13% likelihood) — The refreshed IS may benefit from ECM software updates that adjust catalyst monitoring parameters.
Diagnosis Steps
- Visit a Lexus dealer — The 2022 IS should still be under warranty for most components. Let the dealer handle diagnosis.
- Check for TSBs — Request the dealer search for Technical Service Bulletins specific to P0430 on the refreshed IS.
- Monitor sensor data — Have the dealer review live O2 sensor data on Bank 2 to confirm whether the converter or sensor is the problem.
- Inspect the exhaust system — Particularly on the IS 500, check the V8's more complex exhaust routing for leaks.
Repair Options and Cost Estimates
- Air-Fuel Ratio/O2 Sensor Replacement — $180 to $420 (likely covered under warranty).
- Catalytic Converter Replacement — $1,400 to $3,200. The IS 500's V8 converters are significantly more expensive.
- Exhaust Leak Repair — $100 to $400.
- ECM Software Update — $0 to $150 (free under warranty).
Warranty Coverage
The 2022 Lexus IS is covered by the basic warranty (4 years/50,000 miles), powertrain warranty (6 years/70,000 miles), and the federal emissions warranty (8 years/80,000 miles for catalytic converters). Most P0430 repairs should be warranty-covered.
Prevention Tips
- Use premium fuel (91+ octane recommended for all IS engines)
- Follow oil change intervals with the specified synthetic oil
- Allow the engine to cool after track days or spirited driving sessions
- Address any warning lights or performance changes promptly
- Keep dealer service visits current for software updates and TSBs