P0175 on the 2024 Mazda CX-90: New Platform, New Considerations
The 2024 Mazda CX-90 represents a major leap for Mazda, built on the new Large Architecture platform with a longitudinally-mounted 3.3L turbocharged inline-six engine (CX-90 3.3 Turbo) producing 280-340 hp, or a 2.5L four-cylinder PHEV powertrain. The inline-six is Mazda's first six-cylinder engine in years, and P0175 on this engine has a true Bank 2 because of the six-cylinder configuration — cylinders 4, 5, and 6 make up Bank 2.
As a first-generation vehicle on an all-new platform, the CX-90 may experience some growing pains. P0175 on this new engine should be addressed through warranty service.
Symptoms
- Check engine light illuminated on the digital gauge cluster
- Fuel economy below the 24-28 MPG expected range
- Rough or uneven idle
- Fuel odor from the exhaust
- Turbo response may feel inconsistent
- Possible reduction in available power
- Black exhaust residue
Causes on the CX-90's New 3.3L Turbo I6
1. MAF Sensor Contamination or Calibration — High Likelihood
The CX-90's 3.3L inline-six uses a new MAF sensor configuration matched to its larger displacement and turbocharger. As with any turbo engine, PCV vapors contribute oil contamination to the MAF element. Additionally, being a first-year engine, MAF calibration may not be perfectly optimized for all operating conditions. The inline-six draws significantly more air than the previous 2.5T four-cylinder, making MAF accuracy even more critical for proper fuel metering across all six cylinders.
2. O2 Sensor on Bank 2 — Medium Likelihood
The 3.3L inline-six has dedicated O2 sensors for each bank. Bank 2 (cylinders 4-6) has its own upstream wideband sensor. On a first-year engine, manufacturing variability or assembly contamination can cause premature sensor issues. The sensor's accuracy directly affects fuel trim calculations for the rear three cylinders.
3. ECM Software Calibration — Medium Likelihood
First-year vehicles on new platforms frequently receive ECM software updates as Mazda gathers real-world data. The 3.3L turbo's fuel mapping, sensor thresholds, and adaptation algorithms may be refined through over-the-air or dealer-applied updates. P0175 at low mileage on a CX-90 may be resolvable through a simple software flash.
4. Fuel Injector or Turbo System Issue — Low Likelihood
The 3.3L uses high-pressure direct injection on all six cylinders. An injector with a factory defect on Bank 2 can cause over-delivery. The turbo system's charge pipe routing on the new inline-six layout is also untested at scale, and any boost leak after the MAF can create a rich condition. Both are uncommon on new vehicles but worth checking.
Diagnostic Steps
- Take the CX-90 to a Mazda dealer immediately — this is a warranty repair on a new platform
- Ensure the dealer checks for TSBs and software updates specific to the 3.3L engine
- If self-diagnosing, monitor Bank 2 vs Bank 1 fuel trims for comparison
- Test MAF sensor readings against Mazda's new specifications for the 3.3L
- Check for boost system leaks
Cost Estimates (If Out of Warranty)
- MAF sensor: $150–$320
- O2 sensor: $170–$370
- ECM software update: $0–$150
- Fuel injector (each): $200–$450
All covered under Mazda's 3-year/36,000-mile warranty on the 2024 CX-90.
Dealer Service Is Essential
The CX-90 is an all-new vehicle on an all-new platform. Let Mazda's trained technicians diagnose and repair P0175 using their latest diagnostic equipment and any applicable software updates. This is exactly what your warranty is for, and Mazda needs the real-world feedback to continue refining the 3.3L turbo engine.