Troubleshoot problems with a Toyota RAV4 by checking for common issues, such as malfunctioning oxygen sensors, vent valve failures and check engine light problems. While examining these problems, look for more complex issues that may require fixing.
If the RAV4 check engine light has a problem, one of the sensors might be bad. Open the fuse panel in the driver’s side foot well by pulling it. Locate the access port, and plug the scan tool to retrieve the diagnostic code. Select the stored code from the menu, and use the RAV4 service manual to translate it. Clear all the engine codes, and shut off the check engine light on the RAV4 dashboard.
If the car has an increased emission and poor engine performance, the oxygen sensor might be malfunctioning. Test the oxygen sensor for continuity using a digital voltmeter, and replace it if necessary. If the RAV4 has a vent valve failure, check to see whether the vent valve is clogged. If the troubleshooting code P0446 appears, this indicates a vent valve failure. Fix the problem by replacing canisters and the valves if necessary.
If these repair methods do not solve the problem, contact a Toyota RAV4 professional for assistance.