Two catalytic converters are standard on most US-spec Toyota 4Runner models equipped with the 4.0-liter V6.
In practice, the typical exhaust setup includes a close-coupled catalytic converter near the engine and a secondary converter further downstream in the exhaust flow. Emissions configurations vary by model year and regional market, so some variants may use a single converter or a different arrangement. For an exact count, refer to the vehicle’s VIN or the official service documentation for the specific year and model.
Typical setup for current models
Here’s what you’ll usually find on a modern 4Runner with the 4.0L V6:
- Two catalytic converters in series: a primary (close-coupled) cat near the exhaust manifolds and a secondary downstream cat.
- Oxygen sensors placed before and after the converters to monitor performance and help the engine control system adjust fuel trim.
- Variations can occur by year or regional specification, so check the owner's manual or a Toyota service bulletin for a precise configuration.
This two-cat arrangement helps meet federal emission standards and provides redundancy to ensure proper emission control across the exhaust system.
Variations by year and market
Because Toyota produced the 4Runner across multiple generations and regions, there are some differences in catalytic-converter counts and layouts.
- Most US-market 4Runners with the 4.0L V6 use two catalytic converters.
- Some older or non-US market configurations may employ a single catalytic converter or a different emission-control layout.
To confirm the exact number for a specific vehicle, consult the VIN, owner's manual, or a Toyota technician who can inspect the exhaust components.
Summary
For the typical Toyota 4Runner, expect two catalytic converters in the exhaust system. While two is standard for most 4Runner V6 models, variations exist by year, generation, and market, so verify with vehicle documentation for a specific vehicle.