What Does P0174 Mean on Your 2022 Mercedes-Benz GLE?
A P0174 code on your 2022 Mercedes-Benz GLE (W167) means the engine is running too lean on Bank 2. The 2022 GLE 450 uses the M256 3.0L turbocharged inline-six, while the GLE 350 uses the M264 2.0L turbo-four. At 20,000-50,000 miles, certain components can begin to show wear that causes lean conditions.
Symptoms You Might Notice
- Check engine light on
- Rough or unsteady idle
- Reduced power output
- Lower fuel economy
- Hesitation when accelerating
- Hissing or whistling sounds
Common Causes of P0174 on the 2022 GLE
Both engines share similar failure patterns:
- Boost Leak — Charge pipe connections and intercooler hoses can develop leaks from thermal expansion and age.
- Intake Manifold Leak — Gasket degradation allows unmetered air into the engine.
- MAF Sensor Issue — Oil mist or debris contamination causes incorrect airflow measurement.
- Fuel Delivery Problem — A high-pressure pump losing efficiency or an injector developing carbon buildup.
How to Diagnose the Problem
- Scan all codes with Mercedes-compatible diagnostic software.
- Monitor fuel trim adaptations — above +10% confirms lean.
- Inspect boost connections and charge pipes.
- Check intake manifold gaskets.
- Smoke test the boost and intake system.
- Test fuel pressure under various load conditions.
Repair Options and Estimated Costs
- Boost leak repair: $250–$650.
- Intake manifold gasket: $350–$750.
- MAF sensor replacement: $220–$500.
- Fuel system service: $500–$1,200.
Can You Still Drive?
Light driving is acceptable. Check if your 2022 GLE is still within the 4-year/50,000-mile warranty. If so, visit the dealer. If not, find a qualified independent Mercedes specialist.
Prevention Tips
- Use premium fuel at all times.
- Follow the Mercedes maintenance schedule strictly.
- Inspect boost system connections during service.
- Keep the air filter clean.
- Address warning lights quickly to prevent expensive cascading failures.