What Does P0172 Mean on Your 2024 Chevrolet Silverado?
A P0172 code on the 2024 Chevrolet Silverado 1500 means the engine control module has detected that Bank 1 is running too rich. The 2024 Silverado offers several engine choices including the 2.7L turbo four-cylinder (310 hp), the 5.3L EcoTec3 V8 (355 hp), and the 6.2L EcoTec3 V8 (420 hp). On the V8 engines, Bank 1 is the driver side of the engine. On the 2.7L turbo four-cylinder, there is only one bank.
Running rich means too much fuel is entering the combustion chambers relative to air. This hurts fuel economy on a truck that already drinks a fair amount of gas, and can damage catalytic converters that cost over $1,000 to replace on the Silverado.
Common Symptoms You May Notice
- Check engine light on
- Reduced fuel economy
- Rough or uneven idle
- Black smoke from the exhaust, especially under acceleration
- Strong fuel smell from the tailpipe
- Sluggish performance
Top Causes of P0172 on the 2024 Silverado
- Dirty MAF sensor - On the Silverado, the mass airflow sensor sits in the air intake duct. Road dust and debris contaminate the sensing element, causing it to underreport airflow and trigger over-fueling.
- Leaking fuel injector - The 5.3L and 6.2L V8 engines use port injection and direct injection together. A leaking injector on Bank 1 (driver side) dumps extra fuel into the cylinder.
- Faulty upstream O2 sensor - The Bank 1 Sensor 1 oxygen sensor can degrade over time, feeding incorrect voltage readings to the ECM.
- Fuel pressure regulator malfunction - Abnormally high fuel pressure pushes too much fuel through the injectors across all cylinders.
How to Diagnose the Problem
Scan for codes and check freeze frame data. Review Bank 1 STFT and LTFT values. Negative LTFT values beyond -10% confirm the rich condition.
Start with the air filter. The Silverado's large air filter can trap a lot of debris but also lets contamination reach the MAF sensor over time. Clean the MAF with dedicated MAF cleaner spray.
Use live data to monitor the upstream O2 sensor on Bank 1 (driver side on V8 models). It should oscillate between 0.1V and 0.9V. Check fuel pressure with a gauge; the 5.3L and 6.2L should read approximately 55-60 psi at idle.
If only Bank 1 is affected, focus on Bank 1 injectors and the Bank 1 O2 sensor. If both banks show rich conditions, the MAF or fuel pressure is more likely the cause.
Repair Options and Cost Estimates
- MAF sensor cleaning or replacement: Cleaning is under $10. New sensor costs $55-$175 plus $50-$100 labor.
- Fuel injector replacement: Parts run $40-$100 per injector. Labor is $200-$450 depending on the engine.
- O2 sensor replacement: Parts cost $55-$160. Labor is $80-$160.
- Fuel pressure regulator: Parts are $50-$130. Labor runs $100-$250.
Can You Fix This Yourself?
MAF sensor cleaning is easy on the Silverado and takes about 15 minutes. O2 sensor replacement is moderate difficulty. Fuel injector replacement varies; port injectors are relatively accessible, but direct injection injectors require more expertise.
Prevention Tips
- Replace the air filter every 15,000-20,000 miles or more often in dusty conditions
- Use Top Tier fuel to minimize injector deposits
- Run a fuel system cleaner every 5,000-7,000 miles
- Address check engine lights quickly to protect the catalytic converters