What P0174 Means on Your 2022 Ram 2500
A P0174 code on your 2022 Ram 2500 indicates that Bank 2 is running with a lean air-fuel mixture. The 2022 Ram 2500 offers the 6.4L HEMI V8 (410 hp) as its gas engine option, along with the 6.7L Cummins turbo-diesel inline-six. On the 6.4L HEMI, Bank 2 is the passenger side of the engine. P0174 is specific to gas engines and indicates too much air or insufficient fuel on that bank.
The Ram 2500 is a heavy-duty truck often used for towing and commercial work. A lean condition compromises the engine's ability to produce reliable power under load, which is exactly when you need it most.
Symptoms
- Check engine light on
- Rough idle
- Reduced power, especially under load
- Poor fuel economy
- Engine hesitation or stumbling
- Possible detonation (pinging) under heavy throttle
Common Causes on the 6.4L HEMI
- Exhaust Manifold Leak (30% likelihood) – Like its 5.7L sibling, the 6.4L HEMI can develop exhaust manifold bolt failures. A leak near the Bank 2 O2 sensor creates a false lean reading.
- Vacuum Leak (25% likelihood) – The large intake manifold on the 6.4L has numerous gasket surfaces and vacuum connections that can develop leaks over time.
- Fuel Injector Issue (25% likelihood) – A clogged or failed injector on Bank 2 reduces fuel delivery. The 6.4L's injectors handle significant fuel flow and can wear.
- MAF Sensor Problem (20% likelihood) – A dirty or failing MAF sensor sends incorrect airflow data, causing lean fueling.
Diagnosis
- Compare bank fuel trims – If Bank 2 LTFT is significantly higher than Bank 1, the issue is bank-specific.
- Inspect exhaust manifolds – Look for soot around bolts and listen for ticking on cold starts.
- Smoke test the intake – Find hidden vacuum leaks in the large intake system.
- Test fuel injectors – Perform an injector balance test on Bank 2 cylinders.
- Check MAF sensor – Clean and test readings against specifications.
Repair Costs
- Exhaust manifold repair – Bolt extraction and gasket: $250–$600. Manifold replacement: $500–$1,100.
- Vacuum leak repair – $80–$500.
- Fuel injector – Single: $120–$280. Labor: $200–$400.
- MAF sensor – Cleaning: $10. Replacement: $100–$280.
DIY Feasibility
The Ram 2500's tall engine bay gives reasonable access to the 6.4L HEMI. MAF cleaning is simple. Visual exhaust manifold inspection from below is straightforward. However, exhaust manifold bolt extraction on the 6.4L can be a major project if bolts are seized. Fuel injector work requires proper safety precautions with the fuel system.
Prevention
- Inspect exhaust manifold bolts at every oil change
- Replace the air filter every 20,000 miles or sooner in dusty conditions
- Use quality fuel to keep injectors clean
- Address exhaust ticking sounds immediately
- Follow Ram's recommended maintenance schedule