P0175 on the 2022 Ram 3500 Gas Model
The 2022 Ram 3500 gas variant uses the 6.4L HEMI V8 producing 410 hp and 429 lb-ft of torque — the same engine found in the Ram 2500 gas model. This engine features multi-port fuel injection, VVT, and a true Bank 2 on the passenger side (cylinders 2, 4, 6, 8). P0175 means Bank 2 is running too rich for the ECM's fuel trim system to correct.
Ram 3500 trucks are the hardest-working vehicles in the Ram lineup, often tasked with heavy towing, commercial hauling, and demanding work environments. These conditions accelerate sensor wear and contamination, making P0175 more likely than on lighter-duty vehicles.
Symptoms in a Working Truck
- Check engine light on
- Fuel economy even worse than the typical 10-15 MPG range
- Pronounced rough idle, especially when loaded
- Strong fuel smell from the exhaust
- Black smoke visible when accelerating under load
- Reduced towing power
- Engine may stumble when transitioning from idle to throttle
Root Causes for the 6.4L HEMI in Heavy-Duty Service
1. MAF Sensor Contamination — High Likelihood
The Ram 3500's duty cycle is brutal on the MAF sensor. Work sites, gravel roads, farm environments, and towing kick up enormous amounts of dust and debris. Even with a quality air filter, the MAF sensor accumulates contamination faster than in lighter-duty applications. The 6.4L's high airflow demands mean that MAF errors have a proportionally large impact on fuel delivery. At 25,000-60,000 miles of heavy use, MAF replacement (not just cleaning) is often the lasting fix.
2. O2 Sensor Degradation — Medium Likelihood
The 6.4L HEMI in 3500-class towing duty runs its exhaust system at extreme temperatures. Sustained high-load towing can push exhaust gas temperatures above 1,200 degrees F, which rapidly ages the upstream O2 sensor. A sensor that has lost responsiveness from heat cycling reports inaccurate mixture data, causing the ECM to over-enrich. Heavy towing trucks may need O2 sensor replacement sooner than typical service intervals suggest.
3. Fuel Injector Issues — Medium Likelihood
Under heavy load, the 6.4L's injectors fire at maximum duty cycle for extended periods. This accelerated use pattern causes seal and pintle wear faster than in lighter-duty applications. A leaking or sticky injector on Bank 2 enriches those cylinders. Injector flow testing reveals over-delivering or leaking injectors.
4. Fuel Pressure Regulator — Low Likelihood
The fuel pressure regulator on the 6.4L maintains consistent rail pressure across the demanding load range. If the regulator sticks at a higher-than-specified pressure, all Bank 2 injectors over-deliver. This is uncommon but worth checking if other causes are eliminated, especially after high-mileage heavy-duty use.
Diagnostic Process
- Scan for DTCs with a Stellantis-compatible scanner
- Compare Bank 1 and Bank 2 fuel trims at idle and 2,000 RPM
- Test MAF sensor readings at multiple RPM points
- Monitor O2 sensor waveforms — response time and voltage range
- Check fuel pressure at idle and under load
- Run injector balance test
Repair Costs
- MAF sensor: $90–$230
- O2 sensor: $110–$280
- Fuel injector (each): $80–$200
- Fuel pressure regulator: $130–$300
DIY Potential
The Ram 3500 has ample engine bay space. MAF sensor replacement is straightforward. O2 sensor access requires getting under the truck — a lift or tall jack stands are needed due to the truck's height. Injector and fuel pressure work are intermediate jobs. If under warranty, use the dealer.