P2187 – System Too Lean at Idle (Bank 1): Causes & Fixes

P2187 indicates your engine is running lean (not enough fuel) at idle in Bank 1, commonly due to vacuum leaks, dirty sensors, or fuel pressure issues.

❓ What is P2187?

P2187 – System Too Lean at Idle (Bank 1)
This DTC means the air-fuel mixture is unbalanced—there's too much air or not enough fuel—on one side (Bank 1) of the engine when the car is idling.

⚠️ Symptoms of P2187

• 🚨 Check Engine Light

• 🔁 Rough idling

• ⛽ Poor fuel economy

• 🛑 Hesitation or stalling

• 🌬️ Unstable RPM at idle

🔍 Common Causes of P2187

1. 🌬️ Vacuum leak in intake manifold or hoses

2. 🔌 Faulty Mass Air Flow (MAF) sensor

3. ⚙️ Dirty or stuck PCV valve

4. 💧 Leaking fuel injector or weak fuel pressure

5. 💻 Faulty O2 sensor or ECM software glitch

🛠️ How to Fix P2187

✅ 1. Check for Vacuum Leaks

Use smoke test or spray method to find leaks.
👉 Air Intake Parts →

✅ 2. Clean or Replace MAF Sensor

👉 MAF & MAP Sensors →

✅ 3. Replace PCV Valve or Fuel Injector

👉 Fuel System Components →

🚗 Common Vehicles with P2187

🛒 Useful Nayapurna Links

• Engine & Idle Control Parts

• Hyundai Engine Management

• Tata Fuel & Intake System

• Honda Air/Fuel Sensors

💡 Tips to Remember

• Always scan live fuel trims (LTFT, STFT) before replacing any part

• Clean sensors before replacing—many faults are fixable

• Use original spares for consistent idle and mileage

✅ Conclusion

Code P2187 often signals a vacuum or fuel imbalance issue. Restore stable idle and mileage using trusted spares from nayapurnaonline.com.