Cylinder 3 Pressure Variation Low

Common symptoms

What you'll notice

• Check the ignition system, including spark plugs, ignition coils, and spark plug wires, for any issues or signs of wear.
• Inspect the fuel system and ensure that the fuel injectors are clean and functioning properly.
• Verify that the cylinder 3 fuel injector is receiving the correct amount of fuel and is operating correctly.
• Examine the compression in cylinder 3 and compare it to the other cylinders to identify any potential issues with the cylinder or piston rings.
• Inspect the engine's valve train and ensure that the valves in cylinder 3 are opening and closing properly.

Common causes

Most likely first

1. Faulty spark plug in cylinder 3
2. Ignition coil malfunction in cylinder 3
3. Fuel injector issue in cylinder 3
4. Compression loss in cylinder 3
5. Engine control module (ECM) failure

How to diagnose & fix

Work through it in order

1. Engine misfires or runs rough
2. Decreased engine power or acceleration
3. Poor fuel efficiency
4. Rough idling or stalling
5. Illumination of the check engine light