my Toyota Highlander has a check engine light and won't accelerate properly

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.
• Allow the engine to cool before proceeding.

2. Addressing Error Codes

• Use the OBD-II scanner to retrieve and document any error codes.
• Research the codes to identify potential issues (e.g., P0300 for random misfire, P0171 for lean condition).

3. Clean or Replace the Throttle Body

• Remove the air intake duct to access the throttle body.
• Using throttle body cleaner, spray and clean the inside of the throttle body.
• Reattach the air intake duct securely.

4. Inspect and Replace Air Filter

• Remove the air filter housing cover.
• Take out the old air filter and inspect for dirt and blockages.
• Replace with a new, clean air filter.

5. Check Fuel Pressure

• Locate the fuel pressure test port on the fuel rail.
• Attach the fuel pressure gauge and turn the ignition on (do not start the engine) to read the pressure.
• If pressure is low, consider replacing the fuel pump or checking the fuel filter.

6. Clean or Replace MAF Sensor

• Disconnect the electrical connector from the MAF sensor.
• Remove the sensor from its housing.
• Clean it with MAF sensor cleaner; if damaged, replace it with a new sensor.
• Reconnect the electrical connector.

7. Inspect for Vacuum Leaks

• Visually inspect all vacuum hoses and connections for cracks or disconnections.
• Use a smoke machine or carburetor cleaner around hoses to detect any leaks.
• Replace damaged hoses as necessary.