What Does P0420 Mean on a 2022 Nissan Pathfinder?
The P0420 code on your 2022 Nissan Pathfinder indicates the Bank 1 catalytic converter is not meeting its efficiency target. The completely redesigned 2022 Pathfinder rides on a new platform and is powered by a 3.5L V6 VQ35DD engine producing 284 hp, now paired with a 9-speed automatic transmission replacing the previous CVT. Bank 1 is the rear cylinder bank on this transversely mounted V6. The new platform uses updated exhaust routing and converter placement compared to the previous generation.
As a relatively new vehicle, the 2022 Pathfinder should still be under multiple warranty coverages, making this a dealer repair in most cases.
Symptoms You Might Notice
- Steady check engine light
- Slight fuel economy decrease
- Sulfur odor from exhaust
- Mild power reduction under load
- Emissions test failure
Common Causes on the 2022 Pathfinder
1. Catalytic Converter Degradation
Even on a newer Pathfinder, the 3.5L V6 runs hot under load. If the vehicle has been used for towing, hauling passengers, or frequent highway driving, the converter accumulates thermal stress. The new 9-speed transmission keeps RPMs lower during cruising, which can actually reduce exhaust temperatures compared to the old CVT, but aggressive driving still stresses the converter.
2. Downstream O2 Sensor Malfunction
A defective or sluggish post-cat sensor is a common cause of false P0420 on newer vehicles. The sensor may have shipped with a factory defect or sustained damage from road debris. This is the cheapest fix and should be ruled out first.
3. Software Calibration Issue
The 2022 Pathfinder was a complete redesign, and new platforms often need software refinements. Nissan may have released an ECM update that adjusts P0420 monitoring parameters for the new exhaust system design. A reflash at the dealer could resolve the code.
4. Exhaust Leak
The redesigned exhaust system may have connection points that are not fully sealed. Gasket degradation from heat cycling, or a loose clamp can allow air to enter the exhaust stream and trigger false P0420 readings.
How to Diagnose the Problem
- Visit your Nissan dealer — The 2022 Pathfinder should be under warranty. The dealer can run full diagnostics with CONSULT and check for applicable TSBs.
- Check for software updates — A PCM reflash may be all that is needed.
- O2 sensor data review — Live data comparison of upstream and downstream sensors identifies the faulty component.
- Exhaust system inspection — All joints and gaskets should be checked for leaks.
- Converter efficiency test — Temperature differential and O2 storage tests confirm converter health.
Repair Options
Professional Repair (Recommended)
Your 2022 Pathfinder is covered by the factory warranty (3 years/36,000 miles) and the federal emissions warranty (8 years/80,000 miles for converters). Take it to your Nissan dealer for no-cost diagnosis and repair. The 9-speed transmission integration makes exhaust work dealer-appropriate.
DIY Repair
DIY work on a warranty-age Pathfinder is not advised. Let the dealer handle this to preserve your warranty coverage and avoid out-of-pocket expense.
Estimated Repair Costs
- Catalytic converter replacement: $750 - $1,700 (likely warranty-covered)
- Downstream O2 sensor: $125 - $300 (likely warranty-covered)
- ECM software update: $0 (warranty-covered)
- Exhaust leak repair: $100 - $400
Prevention Tips
- Use quality fuel as recommended in the owner's manual
- Follow the maintenance schedule through the MyNISSAN app
- Report check engine lights to the dealer promptly while under warranty
- If towing regularly, allow cool-down periods before shutting off the engine
- Keep all maintenance records for warranty documentation