P02B3
Cylinder 7 - Fuel Trim at Min Limit
Fuel & air metering
Generic OBD-II
High
What it means
P02B3 means the fuel correction for cylinder 7 has reached its minimum limit — the ECM is subtracting as much fuel as it can but the cylinder still runs rich. This usually points to too much fuel entering that cylinder, from a leaking injector, high fuel pressure, or a sensor biasing the mixture rich.
High
Can I keep driving? Usually driveable, but cylinder 7 is running rich and may idle rough or foul its plug; fix it to avoid wasted fuel and converter damage.
Common symptoms
What you'll notice
- Check-engine light on
- Rough idle or uneven running
- Reduced fuel economy and possible fuel smell
- Hesitation, and sometimes hard starting
Common causes
Most likely first
- Leaking or stuck-open injector on cylinder 7 (adds too much fuel)Likely
- High fuel pressure or a faulty fuel-pressure regulatorCommon
- Faulty oxygen (O2) sensor biasing the mixture richCommon
- MAF sensor over-reporting airflowLess often
- Fuel contamination or oil dilution of the fuelLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame and long-term fuel-trim data to confirm the rich condition on cylinder 7.
- Inspect the cylinder 7 injector for leaking or a stuck-open condition.
- Check fuel pressure against spec and inspect the regulator.
- Test the MAF and upstream O2 sensor readings; check for fuel/oil contamination. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P02B3?+
Short-term yes, but a persistently rich cylinder wastes fuel, can foul the plug, and may harm the catalytic converter. Get it diagnosed soon.
Can I just clear P02B3?+
It returns once fuel trim hits its limit again. The code means the ECM can no longer pull enough fuel to correct the mixture — a real fueling problem.
Related codes
Often seen with P02B3
Read & clear P02B3 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX