What Does P0172 Mean on Your 2023 Honda Ridgeline?
The 2023 Honda Ridgeline carries the same proven 3.5L V6 engine producing 280 horsepower with a 9-speed automatic transmission. P0172 means the ECM has detected a rich fuel condition on Bank 1, the rear cylinder bank on this V6. The engine is getting more fuel than the optimal 14.7:1 air-to-fuel ratio, and the O2 sensor is detecting excess unburned fuel in the exhaust.
On a relatively new 2023 model, this code is less common but still possible. Honda's factory warranty should cover most causes.
Common Symptoms You Might Notice
- Check engine light on
- Fuel economy below the expected 18/24 MPG
- Exhaust has a fuel or sulfur odor
- Black residue on tailpipe
- Slight rough idle
- Reduced throttle response
Top Causes of P0172 on the 2023 Ridgeline
- MAF Sensor Issue (30% likelihood): Contamination or a factory defect can cause the MAF sensor to misread airflow, leading to over-fueling.
- ECM Calibration (25% likelihood): Software updates for fuel trim calibration may be available from Honda for the 2023 model year.
- Upstream O2 Sensor Defect (25% likelihood): A manufacturing defect in the Bank 1 O2 sensor can send inaccurate readings to the ECM.
- Intake Assembly Issue (20% likelihood): A loose clamp, improperly seated gasket, or minor assembly oversight can affect airflow measurements.
How to Diagnose P0172 on Your 2023 Ridgeline
- Visit the dealer under warranty. The 2023 Ridgeline is covered by Honda's 3-year/36,000-mile basic warranty and 5-year/60,000-mile powertrain warranty.
- Ask about TSBs. Your dealer can check for Technical Service Bulletins related to fuel trim on the 2023 Ridgeline.
- Check the air filter. Ensure it is correctly seated and not overly dirty.
- If DIY diagnosing, check fuel trims. Compare Bank 1 and Bank 2 LTFT values with a scan tool.
- Inspect visible intake connections. Look for loose hose clamps or disconnected lines.
Repair Options and Costs
- Warranty repair: $0 at Honda dealership
- MAF sensor cleaning: $10 DIY or $60-$100 at a shop
- MAF sensor replacement: $150-$300 parts and labor
- ECM software update: $0-$150 (often warranty-covered)
- O2 sensor replacement: $200-$420 parts and labor
Can You DIY This Repair?
For a 2023 model under warranty, take it to the dealer. The repair should be free. If outside warranty, MAF sensor cleaning is an easy DIY task. More involved repairs like O2 sensor replacement on the rear bank are better suited for a professional on the Ridgeline.
Prevention Tips
- Follow Honda's maintenance schedule
- Use OEM or equivalent quality air filters
- Avoid aftermarket intake modifications
- Keep up with dealer service visits for software updates
- Use quality fuel from reputable stations