Understanding P0172 on Your 2024 Volvo S60
A P0172 diagnostic trouble code on your 2024 Volvo S60 indicates that the engine control module has detected a rich air-fuel mixture on Bank 1. The 2024 S60 is powered by Volvo's 2.0-liter turbocharged four-cylinder B5 mild-hybrid engine producing 247 hp, paired with a 48-volt integrated starter-generator. This engine uses direct fuel injection and sophisticated fuel management. When the system runs too rich, it means excess fuel is entering the combustion chambers relative to the air supply, reducing efficiency and increasing emissions.
Symptoms You May Notice
- Check engine light activated
- Drop in fuel economy from the expected 26-35 MPG
- Dark or black exhaust smoke
- Rough or irregular idle
- Fuel smell at the tailpipe
- Engine hesitation on acceleration
Most Common Causes of P0172 on the 2024 S60
- Dirty Mass Airflow (MAF) Sensor - The MAF sensor in the intake tract measures incoming air volume. Contamination from PCV oil vapors or environmental debris leads to underreading of airflow, causing the ECM to add excess fuel.
- Faulty Fuel Injectors - Direct-injection fuel injectors operating at high pressures in the B5 engine can develop leaks or fail to close fully, resulting in too much fuel delivered per combustion event.
- Degraded Upstream O2 Sensor - The pre-catalytic converter oxygen sensor on Bank 1 gives the ECM real-time exhaust feedback. A slow or biased sensor causes continuous enrichment.
- Restricted Air Filter - A clogged air filter limits airflow to the turbocharger intake, throwing off the air-fuel ratio and triggering the rich condition code.
How to Diagnose the Problem
Scan the vehicle with an OBD-II tool and confirm the P0172 code. Check for related codes. Examine freeze frame data to understand the engine operating conditions when the code was set. Check Bank 1 short-term and long-term fuel trims via live data. Long-term fuel trim below -8% to -10% confirms the ECM has been compensating for a sustained rich condition. Inspect the air filter visually. Clean or test the MAF sensor. Measure fuel pressure. Monitor the upstream O2 sensor response using a scan tool. If the sensor is stuck high or sluggish, it needs replacement.
Repair Options and What to Expect
On the 2024 S60, cleaning the MAF sensor is a quick, low-cost first step. If the MAF is beyond cleaning, a replacement sensor installs easily. Fuel injector replacement on the 2.0L direct-injection engine is a more involved job requiring intake manifold removal, so it is best done at a shop. O2 sensor replacement is accessible from underneath the car. Air filter replacement is a simple 5-minute DIY task.
Estimated Repair Costs
- MAF Sensor Replacement: $150 - $350 (parts and labor)
- Fuel Injector Replacement: $300 - $720 (parts and labor)
- O2 Sensor Replacement: $200 - $450 (parts and labor)
- Air Filter Replacement: $25 - $55 (DIY)
The S60 is a luxury sedan, so Volvo dealer labor rates run $160-$210 per hour. An independent European car specialist can save you significantly on labor costs.
Prevention Tips
- Change the engine air filter every 15,000 miles per the Volvo maintenance schedule
- Use premium fuel as specified in the owner's manual
- Request MAF sensor inspection during routine oil changes
- Respond to check engine lights promptly to prevent catalytic converter damage
- Follow the recommended Volvo service intervals for optimal engine performance