why does my Toyota Camry XV40 (2007-2011) have a check engine light and runs rough?

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent any electrical issues during repairs.

2. Address Faulty Spark Plugs and Ignition Coils

• Remove Engine Cover: Use a socket set to take off the engine cover.
• Access Spark Plugs: Disconnect ignition coils from the spark plugs.
• Inspect and Replace: Remove spark plugs using a spark plug socket. Inspect for wear or deposits, and replace if necessary. Torque new spark plugs to manufacturer specifications (typically 13-15 lb-ft).
• Inspect Ignition Coils: Check ignition coils for cracks or signs of damage. Replace any faulty coils.

3. Clean or Replace Fuel Injectors

• Remove Fuel Rail: Relieve fuel pressure using the service manual procedure, then disconnect the fuel line and remove the fuel rail.
• Inspect Injectors: Check fuel injectors for clogs or leaks. Clean using a fuel injector cleaning kit or replace if necessary.
• Reinstall Fuel Rail: Reattach the fuel rail and reconnect the fuel line, ensuring no leaks.

4. Inspect and Clean the MAF Sensor

• Locate MAF Sensor: Typically found between the air filter and throttle body.
• Remove Sensor: Disconnect the electrical connector and remove the sensor using a screwdriver.
• Clean Sensor: Use MAF cleaner to gently clean the sensor. Allow it to dry completely before reinstalling.
• Reinstall MAF Sensor: Reattach the sensor and connector.

5. Reconnect Battery and Test

• Reconnect the battery terminals.
• Start the engine and allow it to idle, monitoring for any irregularities.