P02B2
Cylinder 7 - Fuel Trim at Max Limit
Fuel & air metering
Generic OBD-II
High
What it means
P02B2 means the ECM has pushed fuel correction for cylinder 7 all the way to its maximum — it's adding as much fuel as it can and still sees that cylinder running lean. The usual causes are unmetered air (a vacuum or intake leak), a weak or clogged injector, or low fuel pressure. The engine runs rough and can misfire until the lean condition is corrected.
High
Can I keep driving? Drivable but running lean on cylinder 7 — expect rough running and lost power; fix it before it triggers a misfire.
Common symptoms
What you'll notice
- Check-engine light on
- Rough idle and hesitation
- Reduced power and acceleration
- Possible misfire on cylinder 7
Common causes
Most likely first
- Intake or vacuum leak, especially near the cylinder 7 runnerLikely
- Clogged or weak fuel injector on cylinder 7Common
- Low fuel pressure or restricted fuel supplyCommon
- Exhaust leak upstream of the oxygen sensor skewing the readingLess often
- Faulty MAF sensor or a disconnected PCV hoseLess often
How to diagnose & fix
Work through it in order
- Scan and read freeze-frame and fuel-trim data to confirm the correction is maxed out.
- Smoke-test the intake and inspect vacuum lines and the PCV hose for leaks.
- Inspect the cylinder 7 injector — test flow and clean or replace it if weak.
- Check fuel pressure and the fuel filter.
- Inspect for exhaust leaks and check the MAF sensor. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P02B2?+
Short trips are usually fine, but a lean cylinder runs rough and can misfire, risking converter damage over time. Repair it soon.
Can I just clear P02B2?+
It returns until the lean condition on cylinder 7 is fixed — most often a vacuum leak or a weak injector.
Related codes
Often seen with P02B2
Read & clear P02B2 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