P0175 GMC Sierra 1500
System Too Rich (Bank 2) · Powertrain Code · Medium · Repair: Moderate
What is P0175?
The engine is running rich on bank 2. Same causes as P0172 but affecting the opposite cylinder bank.
When the GMC Sierra 1500 triggers code P0175 (system too rich (bank 2)), it typically points to an issue in the powertrain system. Below you'll find the most common causes, symptoms, and repair options specific to the GMC Sierra 1500.
This repair is rated moderate, meaning some experience and specialty tools required.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your GMC Sierra 1500.
Common Causes on GMC Sierra 1500
- Dirty or faulty MAF sensor (Bank 2 running rich)
- Leaking fuel injector on Bank 2 cylinders
- EVAP purge valve stuck open allowing fuel vapor into intake
- Faulty O2 sensor on Bank 2 causing incorrect fuel trim
- Intake manifold gasket leak on Bank 2 side
Symptoms
- Check Engine Light on
- Rich exhaust smell
- Black deposits on spark plugs (Bank 2 cylinders)
- Rough idle
- Decreased fuel economy
Notes for GMC Sierra 1500
When P0172 and P0175 appear together on a GM V8, the MAF sensor or purge valve is almost always the cause since both banks are affected equally.