P03D9
Cylinder 7 Pressure Variation High
Generic OBD-II
Common symptoms
What you'll notice
- Check and replace the spark plugs for cylinder 7.
- Inspect and replace the ignition coil for cylinder 7.
- Test and clean the fuel injectors for cylinder 7.
- Check and replace the fuel filter.
- Perform a compression test on cylinder 7 and inspect for any issues with valves or piston rings.
Common causes
Most likely first
- Faulty ignition coil on cylinder 7
- Problem with fuel injector on cylinder 7
- Clogged or restricted fuel injector on cylinder 7
- Issue with the spark plug on cylinder 7
- Compression problem in cylinder 7
How to diagnose & fix
Work through it in order
- Engine misfires or runs rough
- Loss of power or reduced acceleration
- Rough idling or stalling
- Excessive fuel consumption
- Illuminated check engine light
Read & clear P03D9 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.