Cylinder 4 Pressure Variation Low

Common symptoms

What you'll notice

• Check and clean the fuel injectors or replace them if necessary
• Inspect the spark plugs and replace if worn or faulty
• Test and replace the ignition coil for cylinder 4 if faulty
• Perform a compression test on cylinder 4 and inspect for any leaks or issues with the piston rings or valves

Common causes

Most likely first

1. Fuel injector malfunction
2. Spark plug misfire
3. Low compression in cylinder 4
4. Ignition coil failure
5. Faulty engine control module (ECM)

How to diagnose & fix

Work through it in order

1. Misfiring or rough idle
2. Decreased engine performance or power loss
3. Engine stalling or hesitation
4. Increased fuel consumption
5. Difficulty starting the vehicle