Cylinder 2 - Fuel Trim at Min Limit
What it means
P029F means the ECM has had to pull cylinder 2's fuel trim all the way to its minimum limit — it's removing as much fuel as it can and still sees the cylinder running rich. The usual cause is a leaking injector or over-pressure fuel delivery adding more fuel than the cylinder needs. The engine runs rough and rich, which wastes fuel and, if left unaddressed, can foul plugs and harm the catalytic converter.
Can I keep driving? Driveable but running rich on cylinder 2 — the ECM has cut fuel as far as it can; expect rough running, and long-term rich operation can foul plugs and stress the converter.
Common symptoms
What you'll notice
- Check-engine light on
- Rough idle or uneven running
- Rich exhaust smell or black smoke
- Reduced fuel economy
Common causes
Most likely first
- Leaking or dripping cylinder-2 fuel injector (adding excess fuel)Likely
- Excessive fuel pressureCommon
- Fuel-diluted engine oil or contaminated fuelCommon
- Injector or fuel-control fault on cylinder 2Less often
- Skewed MAF or O2 sensor reading (least likely)Less often
How to diagnose & fix
Work through it in order
- Read fuel-trim PIDs and confirm cylinder 2's trim is pinned at its minimum (ECM removing fuel).
- Inspect the cylinder-2 injector for leaking — a leak-down or balance test helps.
- Check fuel pressure against spec for an over-pressure condition.
- Look for fuel dilution in the oil and verify fuel quality.
- Replace the leaking injector or correct the over-fuel source. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P029F?+
Can I just clear P029F?+
Related codes
Often seen with P029F
Read & clear P029F yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.