What is Hyundai P0171?
P0171 means the ECM detected the air-fuel mixture is too lean on Bank 1 — too much air or not enough fuel. The ECM tries to compensate by adding fuel (positive long-term fuel trim). On Hyundai Kappa and Nu petrol engines this is most commonly caused by a vacuum leak allowing unmetered air to enter after the MAF sensor, or a dirty MAF sensor giving a low reading.
Symptoms of P0171 on Hyundai
Engine idles roughly or surges due to lean mixture.
Paradoxically, lean conditions reduce economy as ECM over-compensates.
Engine stumbles under light acceleration.
MIL on — P0171 is a monitored emission fault.
Common Causes of Hyundai P0171
How to Fix P0171 on Hyundai
Check long-term fuel trim (LTFT) values with a scanner — LTFT above +10% confirms lean condition. Spray MAF cleaner to see if reading improves. Check intake hoses carefully for cracks. Use smoke machine test or carb cleaner spray around intake joints to locate vacuum leaks. If vacuum-tight and MAF is clean, test fuel pressure.
⚡ Book Professional Diagnosis — ₹499 onwards
HT ECM Solutions · Bachupally, Hyderabad · Same-day service · Written report
Hyundai Models That Get P0171
This fault code commonly affects: i20, Creta, Verna, i10, Tucson, Alcazar, Venue, Aura. If your Hyundai is showing this code, bring it to HT ECM Solutions in Bachupally, Hyderabad for same-day professional diagnosis.