P0175 on the 2020 Nissan Murano V6
The 2020 Nissan Murano uses the VQ35DE 3.5L V6 engine producing 260 hp, paired with the Xtronic CVT. This engine uses multi-port fuel injection and variable valve timing for a balance of power and efficiency. Bank 2 is the front cylinder bank (cylinders 1, 3, 5). P0175 means the ECM has detected that Bank 2 fuel trims are consistently running rich, with more fuel being delivered than the optimal 14.7:1 ratio requires.
Symptoms to Watch For
- Check engine light illuminated
- Fuel economy below the rated 20-28 MPG
- Rough or slightly lumpy idle
- Black soot at the tailpipe
- Reduced power during acceleration
- Fuel odor from exhaust area
- Possible misfires at idle
Common Causes on the 2020 Murano
1. Contaminated MAF Sensor (High Likelihood)
The Murano's VQ35DE relies on accurate MAF readings for fuel delivery calculations. At 40,000-70,000 miles typical of 2020 models, the MAF sensor has accumulated contamination from PCV oil vapor and airborne particles. The Murano's air intake design draws air from near the front bumper area, which can bring in road spray and fine debris in wet conditions. A contaminated sensor underestimates airflow and leads to over-fueling. MAF cleaning is the cheapest and most effective first step.
2. Aging Upstream O2 Sensor on Bank 2 (Medium Likelihood)
The Bank 2 upstream oxygen sensor monitors exhaust gas composition from the front three cylinders. At the mileage range of 2020 models, the sensor may be developing sluggish response from heat degradation. The VQ35DE in the Murano runs at similar temperatures to the Maxima version but with slightly less aggressive tuning. Test sensor response time with a graphing scan tool -- response should be under 150ms at operating temperature.
3. Fuel Injector Leak on Bank 2 (Medium Likelihood)
Port fuel injectors for cylinders 1, 3, and 5 can develop minor leaks at the seals or pintle after years of heat cycling. The leak allows fuel to drip into the intake port when the injector should be closed, adding unmetered fuel. Check for fuel odor near the intake manifold and perform a fuel pressure leak-down test (pressure should hold steady for 5+ minutes after shutdown).
4. Exhaust Manifold Gasket Leak (Low Likelihood)
A leak in the front exhaust manifold gasket can allow outside air to be drawn past the O2 sensor, causing it to read lean. The ECM responds by adding fuel, creating an actual rich condition. Listen for ticking or hissing sounds from the front of the engine at cold startup, which may diminish as the engine warms and metals expand to seal the leak temporarily.
CVT Interaction
The Murano's CVT adjusts engine RPM for optimal efficiency and smooth operation. When the engine runs rich, power output drops slightly, and the CVT compensates by adjusting its ratio strategy. Murano owners may notice the CVT holding higher RPMs during acceleration or a general feeling of sluggishness. These symptoms resolve once P0175 is corrected.
Diagnostic Steps
- Scan for all codes. Check for P0172 to determine if the issue is bank-specific or system-wide.
- Monitor Bank 2 STFT and LTFT data. LTFT below -10% confirms chronic enrichment.
- Clean the MAF sensor and clear codes.
- Graph the Bank 2 upstream O2 sensor for response time.
- Perform fuel pressure testing and injector leak-down test.
- Inspect front exhaust manifold gasket for leaks.
Repair Costs
MAF cleaning: $10-$15. MAF replacement: $120-$260. O2 sensor: $150-$320. Fuel injector: $120-$260 each. Exhaust manifold gasket: $200-$450. Diagnostic fee: $80-$140/hour.