how to diagnose a misfire in my Ram 1500 DT (2019-Present) with code P0302?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety.
• Allow the engine to cool before beginning work.

2. Inspect Spark Plug

• Remove the engine cover if necessary.
• Disconnect the ignition coil connector and unscrew the ignition coil from cylinder 2.
• Remove the spark plug using a spark plug socket, examine for wear, cracks, or fouling.
• Replace the spark plug if damaged.

3. Test and Replace Ignition Coil

• Using a multimeter, set it to measure resistance.
• Check the resistance of the ignition coil for cylinder 2; compare with manufacturer specifications.
• If the coil is outside of specifications, replace it with a new coil.
• Reinstall the ignition coil and reconnect the connector.

4. Perform Compression Test

• Remove the spark plug from cylinder 2.
• Insert the compression gauge into the spark plug hole.
• Crank the engine and observe the gauge reading.
• Compare the readings to the manufacturer's specifications; if low, further investigation into the cylinder is needed.

5. Inspect Fuel Injector

• Use a fuel injector cleaning kit to test the injector's flow.
• If the injector is clogged or malfunctioning, replace it with a new injector.
• Reinstall the fuel injector and reconnect any fuel lines.

6. Check for Vacuum Leaks

• Inspect all vacuum hoses for cracks or disconnections.
• Use a smoke machine or carburetor cleaner to detect leaks around the intake manifold.
• Repair or replace any damaged hoses or gaskets found.