P02BA
Cylinder 9 Fuel Trim at Max Limit
Generic OBD-II
Common symptoms
What you'll notice
- Check and clean fuel injectors in cylinder 9
- Inspect and replace oxygen sensor in cylinder 9
- Inspect and clean mass air flow sensor
- Check and replace fuel pump in cylinder 9
- Perform a thorough inspection of the cylinder 9 ignition system (for petrol engines)
Common causes
Most likely first
- Faulty oxygen sensor
- Fuel injector issues
- Ignition coil malfunction
- Dirty or clogged fuel injectors
- Vacuum leak
How to diagnose & fix
Work through it in order
- Poor engine performance, including reduced power and acceleration
- Rough idle or stalling at idle
- Increased fuel consumption
- Misfire in cylinder 9
- Engine hesitation or hesitation on acceleration
Read & clear P02BA yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.