OBD codes / P0420 / Toyota RAV4
P0420 on a Toyota RAV4
Catalyst System Efficiency Below Threshold (Bank 1)
2.4L 2AZ-FE and 2.5L 2AR-FE fours plus the 3.5L 2GR-FE V6 (2006-2012).
What P0420 usually means on a RAV4
On the RAV4, P0420 is a bank 1 catalyst-efficiency code that shows up mostly on higher-mileage four-cylinders as the factory converter tires out. The downstream oxygen sensor stops seeing the exhaust get cleaned up and the ECU flags the cat. It's a gradual, mileage-driven code, not a sudden breakdown, and the RAV4's steady highway use tends to bring it on around the six-figure mark. The check-engine light stays on with no real change in how the crossover drives.
Most likely causes on this model
- Aged original catalytic converter
The 2AR-FE RAV4 commonly reaches high mileage on its first cat, and efficiency simply declines.
- Slow downstream O2 sensor
A tired Denso rear sensor can mimic a failing cat, so confirm the sensor before replacing the converter.
- 2AZ-FE oil consumption
The 2006-2008 four can burn oil that fouls the catalyst substrate and shortens its life.
- Exhaust leak ahead of the cat
A rusted flex pipe or manifold gasket admits air and skews the reading on older RAV4s.
- Lingering misfire or lean run
Raw fuel from a weak coil or lean condition overheats the cat; clear those faults first.
What it costs on a RAV4
A direct-fit converter for a four-cylinder RAV4 runs a few hundred dollars in parts and installs quickly since the cat is accessible under the vehicle. The 2GR-FE V6 raises the cost because it uses two converters. Always test the rear O2 sensor and check for exhaust leaks first, so you don't buy a cat the RAV4 doesn't need.
RAV4 owners also ask
Does P0420 mean I need a new catalytic converter right away?
Not necessarily — a lazy rear O2 sensor or an exhaust leak can set it too. On a high-mileage RAV4 with the original cat, the converter is the likely cause, but have it confirmed before spending on one.
Will my RAV4 pass emissions with P0420 set?
No — the catalyst monitor reads failed or not-ready, which is an automatic emissions failure in most states. The RAV4 drives normally, but you'll need it fixed to renew registration.
Year, engine and mileage change the answer. Get a diagnosis for your RAV4 — 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 P0420 behavior is covered on the main P0420 page. Confirm with a scan tool before buying parts.