P0171 on Nissan: System Too Lean (Bank 1)
Severity: 2 of 4
Usually drivable in the short term if the car runs well and the light is steady. Get it fixed soon, because a lean engine can misfire and run hot. If you get misfire codes or the light flashes, park it.
Estimate range covers the repairs listed below; see the cost breakdown. A flashing check engine light, a hot temperature gauge, or brakes that feel different mean stop driving and get help.
What P0171 usually means on a Nissan
Nissan lean codes are frequently traced to MAF sensors and intake air leaks, including cracked intake boots. On V6 models P0171 and P0174 commonly appear together.
Most likely causes on Nissan vehicles
- Dirty or failing MAF sensor
- Intake boot or vacuum leak
- Low fuel pressure
Order reflects cost and likelihood in general; your vehicle may differ. Confirm with testing before buying parts.
Nissan specific tips
- Clean or test the MAF sensor with live data.
- After throttle or intake work, perform the Nissan idle relearn.
Estimated repair cost
This is an estimate, built from typical parts price ranges plus labor hours times an assumed shop rate of $110 to $190 per hour. Actual prices vary by vehicle, region, and shop. Diagnosis fees are often extra.
| Repair | Parts | Labor | Estimate (low / high) |
|---|---|---|---|
| Vacuum or PCV hose | $10 to $80 | 0.3 to 1.0 h | $10 + 0.3 × $110 = $43 $80 + 1.0 × $190 = $270 |
| MAF sensor cleaning or replacement | $10 to $250 | 0.2 to 0.5 h | $10 + 0.2 × $110 = $32 $250 + 0.5 × $190 = $345 |
| Intake manifold gasket | $20 to $150 | 1.0 to 4.0 h | $20 + 1.0 × $110 = $130 $150 + 4.0 × $190 = $910 |
| Fuel pump | $120 to $600 | 1.5 to 3.5 h | $120 + 1.5 × $110 = $285 $600 + 3.5 × $190 = $1,265 |
Costs are generic for this code; parts and labor on some Nissan models may run higher.
Watch a repair video
System Too Lean: Code P0171 or P0174 (1A Auto). Third-party video, loads from YouTube (privacy-enhanced mode) only when you press play. Procedures vary by vehicle. Search YouTube for “P0171 Nissan fix” videos.
Repair manuals
Step-by-step service manuals for Nissan with torque specs and wiring diagrams:
Haynes manuals for Nissan Chilton manuals
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Check Nissan recalls
Enter your VIN at the NHTSA recall lookup before paying for repairs.
FAQ
Will a new MAF fix my Nissan P0171?
Often, if testing points to it. Avoid replacing it on a guess.
Read the full P0171 guide or more Nissan check engine notes.