P0175 on the 2023 Honda Pilot
A P0175 code on your 2023 Honda Pilot means the ECM has detected a rich condition on bank 2 — excess fuel in the combustion mixture. The 2023 Pilot is the first year of the 4th generation, featuring a completely new 3.5L V6 engine with direct injection (285 hp, 262 lb-ft) and a 10-speed automatic transmission. This new engine represents a significant evolution from the previous port-injected 3.5L, and the switch to direct injection changes the common P0175 failure modes.
Symptoms on the 2023 Pilot
- Check engine light on the digital instrument cluster
- Fuel smell from the exhaust
- Rough or unsteady idle
- Black smoke or soot at the exhaust tips
- Fuel economy drops below the rated 19–26 mpg
- Possible misfire sensation under light throttle
Causes Specific to the 2023 Pilot
1. Defective O2 Sensor (High Likelihood)
The 2023 Pilot's new 3.5L direct-injection V6 uses dedicated O2 sensors for each bank. A factory-defective bank 2 sensor that reads falsely lean prompts the ECM to add fuel, creating an actual rich condition. On a first-model-year vehicle with a new engine design, early sensor issues are not uncommon. The wideband air-fuel ratio sensors upstream are the primary fuel control sensors and the most likely culprits.
2. Direct Injector Leak (Medium Likelihood)
The 2023 Pilot is the first Pilot to use direct fuel injection on the V6. Direct injectors operate at extremely high pressures (2,000+ psi) and are more susceptible to sealing issues than port injectors. A bank 2 injector that doesn't fully close between injection events drips fuel into the combustion chamber. As a first-year direct injection implementation, early injector issues are possible. The dealer can perform injector leak-down tests to identify a faulty unit.
3. Fuel Pressure Control Fault (Medium Likelihood)
The new direct injection system uses a cam-driven high-pressure fuel pump with electronic pressure regulation. A faulty fuel pressure sensor, pressure control solenoid, or HPFP can cause elevated rail pressure, resulting in excess fuel delivery across bank 2. On a first-year design, software calibration may also be a factor — Honda may release an ECM update that adjusts fuel pressure targeting.
4. EVAP Purge Valve Issue (Low Likelihood)
A purge valve stuck in the open position feeds fuel vapor from the EVAP canister into the intake continuously, adding unmetered fuel. On a new vehicle, this would be a manufacturing defect. The dealer can command the purge valve on and off to verify operation.
Diagnostic Steps
- Check for TSBs — As a new model with a new engine, Honda may have published guidance for P0175. Always check for available software updates.
- Monitor fuel trims — Compare bank 1 and bank 2 LTFT. Negative LTFT below -10% on bank 2 alone confirms a bank-specific rich condition.
- Test O2 sensors — Compare waveforms between bank 1 and bank 2 sensors for asymmetry.
- Verify fuel pressure — Monitor high-pressure rail data during various driving conditions.
- Inspect injectors — Use the dealer's scan tool to perform injector balance and leak-down tests.
Cost Estimates (If Not Warranty)
- O2 sensor replacement: $130–$320
- Fuel injector replacement: $200–$500 per injector (direct injection)
- Fuel pressure sensor/solenoid: $170–$380
- EVAP purge valve: $90–$210
Full Warranty Coverage
Your 2023 Pilot is covered by Honda's 3-year/36,000-mile basic warranty and 5-year/60,000-mile powertrain warranty. The P0175 code involves fuel system and emissions components fully covered under warranty. O2 sensors have additional coverage under the 8-year/80,000-mile federal emissions warranty. Take it to your Honda dealer for a no-cost diagnosis and repair.
Should You Keep Driving?
Short-term driving is fine, but schedule a dealer appointment within a week. The new direct injection V6 is a sophisticated engine, and running rich can foul spark plugs, contaminate oil, and damage the catalytic converters (which are expensive on a V6 SUV). Since the repair is free under warranty, there's no reason to delay.