why is my Toyota RAV4 XA40 (2013-2018) engine running rough at idle

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, fuel pressure gauge, multimeter.
• Disconnect the negative battery terminal to prevent electrical shock.
• Allow the engine to cool down before starting work.

2. Replace Spark Plugs

• Remove the ignition coil by unscrewing the bolts and disconnecting the electrical connector.
• Use a spark plug socket to remove the old spark plugs.
• Inspect and clean the spark plug sockets of any debris.
• Install new spark plugs by hand, then torque them to the manufacturer's specifications (usually around 13-15 lb-ft).
• Reinstall the ignition coils, ensuring proper electrical connection.

3. Check and Replace Air Filter

• Locate the air filter housing and open it by unclipping the cover.
• Remove the old air filter and inspect for dirt or damage.
• Install a new air filter, ensuring it fits snugly in the housing.
• Close the housing cover and secure it with clips.

4. Inspect and Repair Vacuum Leaks

• Visually inspect all vacuum hoses for cracks or disconnections.
• If any are found, replace the damaged hoses with new ones.
• Use a smoke machine or carburetor cleaner around hoses to check for leaks while the engine is running.

5. Test and Adjust Fuel Pressure

• Connect a fuel pressure gauge to the fuel rail's test port.
• Start the engine and observe the pressure reading; it should match manufacturer specifications (around 50-60 psi for the RAV4).
• If pressure is low, check the fuel pump and filter for blockages or malfunction.