What Does P0172 Mean on Your 2024 Kia Carnival?
When your 2024 Kia Carnival triggers a P0172 code, the engine control module has detected that Bank 1 of your 3.5-liter Lambda III V6 engine is running too rich. This engine produces 290 horsepower with gasoline direct injection. Bank 1 is the side of the V6 with cylinder number 1. A rich condition means too much fuel relative to air. The ECM adjusts fuel delivery using oxygen sensor feedback, and P0172 triggers when those corrections reach their limits.
Symptoms You Might Notice
- Check engine light illuminated
- Fuel economy below the rated 22 mpg combined
- Black or dark exhaust smoke
- Rough idle or vibration
- Reduced power or hesitation
- Gasoline odor from the exhaust
Common Causes of P0172 on the 2024 Carnival
- Contaminated MAF Sensor — Road debris or manufacturing residue can contaminate the mass airflow sensor, even on a new vehicle, causing incorrect readings.
- EVAP Purge Valve Stuck Open — A documented Kia issue where the purge valve fails open, flooding the intake with fuel vapors.
- Defective Oxygen Sensor (Bank 1) — A factory-defective or prematurely failing O2 sensor provides inaccurate data to the ECM.
- ECM Software Update — Calibration updates may be available for the 2024 model year's Lambda III engine.
How to Diagnose the Problem
- Visit your Kia dealer — The 2024 Carnival is under full warranty. Free diagnosis, TSB checks, and software updates.
- Check both banks — P0175 alongside P0172 suggests a system-wide cause.
- Monitor fuel trims — Bank 1 LTFT below -10% confirms the rich condition.
- Inspect the MAF sensor — At idle, expect about 6-11 g/s for the 3.5L V6.
- Check fuel rail pressure — Monitor GDI system pressures through the scan tool.
Repair Options and Estimated Costs
- ECM software update — $0 under warranty
- MAF sensor cleaning or replacement — $10-$290 ($0 under warranty)
- EVAP purge valve replacement — $90-$220 ($0 under warranty)
- Oxygen sensor replacement — $180-$370 ($0 under warranty)
- GDI fuel injector service — $360-$780 ($0 under warranty)
All P0172 repairs are covered under Kia's factory warranty on the 2024 Carnival.
Prevention Tips
- Follow the Kia maintenance schedule
- Don't overfill the gas tank
- Use Top Tier gasoline for the GDI engine
- Report check engine lights to your dealer promptly
- Keep service records for warranty documentation