P0174 on the 2022 Volvo S60: What's Going On
When your 2022 Volvo S60 throws a P0174 code, the engine control module is telling you that bank 2 is running lean — the combustion mixture has more air than the ideal 14.7:1 stoichiometric ratio calls for. The 2022 S60 rides on Volvo's SPA platform and comes with either the T5 (2.0L turbo, 247 hp) or T6 (2.0L twin-charged, 316 hp) engine. Both are direct-injected four-cylinders that rely on precise fuel metering to operate efficiently. The T6 variant adds a supercharger on top of the turbocharger, creating additional plumbing where leaks can develop.
Symptoms You'll Notice
- Check engine light illuminated steadily
- Rough or unsteady idle, especially at cold startup
- Acceleration feels flat or hesitant
- Fuel economy drops below the expected 25–32 mpg range
- Occasional stumble or misfire under light throttle
What Causes P0174 on the 2022 S60
1. Vacuum or Boost Leaks (High Likelihood)
On the S60's turbocharged 2.0L engine, boost leaks are the number-one cause of lean codes. The intercooler piping, silicone hose connections, and the diverter valve are all potential leak points. On the T6 model, the additional supercharger plumbing adds more potential failure points. The PCV system integrated into the valve cover is another notorious source of vacuum leaks on Volvo's modular four-cylinder. A thorough smoke test is essential — it can reveal leaks that are invisible to the naked eye.
2. Dirty or Failing MAF Sensor (Medium Likelihood)
The mass airflow sensor sits between the air filter and turbo inlet on the S60. Over time, oil vapor from the crankcase ventilation system deposits residue on the hot-wire element, causing underreporting of airflow. This leads the ECM to inject less fuel than needed. A can of MAF cleaner spray and 10 minutes of work can often resolve this. If the sensor is electrically faulty, a replacement OEM MAF for the S60 runs $140–$220.
3. Fuel Pressure Issues (Medium Likelihood)
The S60's direct injection system runs at extremely high pressures through a cam-driven high-pressure fuel pump. If the HPFP lobes wear or the pump internals degrade, fuel rail pressure drops and the engine can't deliver enough fuel. This is more common under heavy load conditions. Monitoring fuel rail pressure with a Volvo-compatible scan tool during a test drive will confirm or rule out this cause.
4. Intake Manifold Gasket (Low Likelihood)
The plastic intake manifold on the 2.0L engine can potentially develop a gasket leak, though this is uncommon at the 2022 model's age. It's more of a concern on higher-mileage examples. If all other causes are ruled out, an intake manifold pressure test can identify a gasket failure.
How to Diagnose P0174
- Read all stored codes — Check if P0171 (bank 1 lean) is also present. Both codes together suggest a systemic issue like a MAF or fuel pump problem.
- Monitor fuel trims — Use a scan tool to watch STFT and LTFT on bank 2. Consistently positive values above 12-15% confirm the lean condition.
- Smoke test — Pressurize the intake and boost piping system with smoke. Watch closely around intercooler connections, charge pipes, and the PCV system.
- Clean/test MAF sensor — Remove the MAF, inspect for oil contamination, and clean with dedicated MAF cleaner.
- Check fuel pressure — Monitor HPFP output during idle and under load. Compare to Volvo's specifications.
Repair Cost Breakdown
The S60 is a luxury sedan, and parts pricing reflects that:
- Vacuum/boost leak repair: $150–$500
- MAF sensor replacement: $190–$400
- High-pressure fuel pump: $650–$1,200
- Intake manifold gasket: $400–$750
DIY Feasibility
The S60's engine bay is tight but workable for basic diagnostics. Cleaning the MAF sensor and inspecting boost hoses are beginner-level DIY tasks. Smoke testing requires equipment but can be done with a $40 DIY smoke machine kit. Fuel pump replacement and detailed turbo plumbing work are better left to a Volvo specialist or experienced European car mechanic.
Should You Keep Driving?
You can drive your S60 with P0174 in the short term, but address it within a couple of weeks. A lean condition raises exhaust gas temperatures and can damage the catalytic converter over time — a part that costs $1,500+ on a Volvo S60. Avoid aggressive driving and heavy loads until the repair is completed.