P0171 on the 2023 Kia Telluride
Your 2023 Kia Telluride has set a P0171 code, meaning the 3.8-liter Lambda II V6 engine is running lean on Bank 1. This V6 produces 291 horsepower and has two cylinder banks. Bank 1 contains cylinder 1 on the rear bank near the firewall.
The ECU monitors the air-fuel ratio via the Bank 1 upstream oxygen sensor. When long-term fuel trim corrections on Bank 1 exceed their limits because the mixture is too lean, P0171 is stored.
Symptoms
- Check engine light on
- Rough or vibrating idle
- Hesitation under acceleration
- Decreased fuel economy
- Possible stalling at low RPM
- Hissing from the engine bay
Common Causes
- Vacuum Leaks - Intake manifold gaskets, vacuum hoses, and connections specific to the Bank 1 side are the most common cause.
- MAF Sensor Issues - Contaminated or faulty MAF sensor sends wrong airflow data to the ECU.
- Fuel Injector Problems - A clogged injector on Bank 1 restricts fuel flow to those cylinders.
- Fuel Pressure Issues - A weak fuel pump or failing regulator reduces fuel delivery.
Diagnosis
- Scan all codes - Check for P0174 and Bank 1 misfire codes.
- Compare bank fuel trims - Single-bank lean vs. both banks lean changes the diagnostic path.
- Smoke test - Find vacuum leaks in the intake system.
- Test MAF and fuel pressure - Verify both meet V6 specifications.
- Injector balance test - Check flow rates on Bank 1 injectors.
Repair Costs
- Vacuum hose or gasket repair - $75 to $325
- MAF sensor replacement - $175 to $400
- Fuel injector replacement - $325 to $650
- Fuel pump replacement - $525 to $925
Diagnostic fee: $120 to $175.
Warranty Coverage
Your 2023 Telluride is under Kia's 5-year/60,000-mile basic warranty and 10-year/100,000-mile powertrain warranty. Schedule a dealer appointment for no-cost repair.
Prevention Tips
- Follow Kia's maintenance schedule
- Replace air filters on time
- Use top-tier gasoline
- Inspect vacuum lines at service visits
- Don't ignore subtle idle or performance changes