What Does P0172 Mean on Your 2024 Toyota 4Runner?
The 2024 Toyota 4Runner received a complete redesign, powered by the new 2.4L turbocharged inline-4 producing 278 hp, or a hybrid i-FORCE MAX variant. This replaces the venerable 4.0L V6. P0172 means the ECM detected a rich fuel condition on Bank 1. The inline-4 turbo has one bank covering all four cylinders.
As a completely new platform, the 2024 4Runner may have fuel trim calibration updates available. This should be covered under Toyota's factory warranty.
Common Symptoms You Might Notice
- Check engine light on
- Fuel economy below EPA estimates
- Faint fuel smell from exhaust
- Slight rough idle
- Minor hesitation on acceleration
- Black residue on tailpipe
Top Causes of P0172 on the 2024 4Runner
- ECM Software Calibration (35% likelihood): The new turbo engine on the 4Runner platform may need fuel map refinements through a software update.
- MAF Sensor Issue (25% likelihood): Factory contamination or a defective MAF sensor can cause inaccurate airflow readings on the turbo engine.
- Faulty O2 Sensor (20% likelihood): A manufacturing defect in the upstream O2 sensor can cause incorrect fuel trim feedback.
- Turbo Boost System Leak (20% likelihood): Loose intercooler connections or charge piping from assembly can introduce unmetered air.
How to Diagnose P0172 on Your 2024 4Runner
- Visit the Toyota dealer. The 2024 4Runner is fully covered under warranty.
- Ask about TSBs. Toyota may have bulletins for the new turbo engine's fuel management.
- Check the air filter. Ensure proper installation, especially if the vehicle has been off-road.
- Inspect turbo plumbing visually. Look for loose connections.
Repair Options and Costs
- Warranty repair: $0 at Toyota dealership
- ECM software update: $0-$150
- MAF sensor cleaning: $10 DIY or $60-$110
- MAF sensor replacement: $160-$320 parts and labor
- O2 sensor replacement: $190-$400 parts and labor
- Boost leak repair: $75-$350
Can You DIY This Repair?
Take the 2024 4Runner to the dealer under warranty. The repair should be free. The new turbo engine bay is well organized but DIY work on a new vehicle can complicate warranty coverage.
Prevention Tips
- Follow Toyota's maintenance schedule for the new turbo engine
- Replace air filters more frequently with off-road use
- Keep up with dealer software updates
- Use quality fuel
- Avoid aftermarket intake modifications