my Toyota Tacoma N300 (2016-Present) has a check engine light with code P0301, what to do?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface, and the engine is off and cooled down.
• Disconnect the negative battery terminal to prevent electrical shocks.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1 by unscrewing the mounting bolt and disconnecting the electrical connector.
• Extract the spark plug using a spark plug socket; inspect it for wear or damage.
• If necessary, replace it with a new spark plug, ensuring it is gapped to the manufacturer specifications (typically around 0.043 inches for Toyota).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Test and Replace Ignition Coil

• If the spark plug is functioning correctly, use a multimeter to check the resistance of the ignition coil. Compare readings to specifications from the repair manual.
• If the ignition coil is faulty, replace it with a new unit.
• Reassemble the ignition coil and secure it in place.

4. Inspect and Replace Fuel Injector

• Disconnect the fuel injector connector for cylinder 1.
• Use a noid light to check if the injector is receiving a signal. If not, further electrical diagnostics may be needed.
• If the injector is malfunctioning, remove it from the fuel rail and replace it with a new injector.
• Ensure all connections are secure when reinstalling the fuel injector.

5. Compression Test

• If misfire persists, conduct a compression test on cylinder 1.
• If compression is low, consider performing a cylinder leak-down test to identify potential internal engine issues.