P0175 Chevy Silverado: System Too Rich Bank 2 Fix

P0175 on a Chevy Silverado indicates the ECM has detected a rich air/fuel mixture on Bank 2 — the passenger side bank on most GM V8 engines. It’s the Bank 2 equivalent of P0172. Here’s how to diagnose it on 4.8L, 5.3L, and 6.0L Vortec trucks.

What P0175 Means

The ECM monitors both upstream oxygen sensors and uses their signals to manage fuel delivery via closed-loop fuel control. When the Bank 2 O2 sensor (passenger side) consistently sees a rich exhaust mixture, P0175 is stored. Check short-term and long-term fuel trims on Bank 2 with a scanner for accurate diagnosis.

Most Common Causes on GM Trucks

P0175 on Silverado/Sierra is most commonly caused by: a dirty or failed MAF sensor (affects both banks equally), a leaking fuel injector on the Bank 2 side (cylinders 2, 4, 6, 8 on a typical LS-architecture V8), a failed upstream Bank 2 O2 sensor, or a clogged PCV system. When P0175 appears with P0172, start with the MAF sensor and fuel pressure — these are global (both-bank) causes.

Diagnosis Steps

Check fuel trim data for Bank 2 STFT and LTFT. A LTFT of -10% or more negative indicates the ECM is removing fuel to compensate for a rich condition. Clean the MAF sensor first — it’s the quickest and cheapest fix. If both P0172 and P0175 are set, the MAF or fuel pressure regulator is the most likely cause. If only P0175, focus on Bank 2 injectors and the Bank 2 upstream O2 sensor.

Repair Costs

MAF sensor cleaning: free (use MAF cleaner spray). MAF sensor replacement: $80–150 parts. Fuel injector replacement: $30–80 per injector. Bank 2 upstream O2 sensor: $25–60 parts. PCV valve: $8–15. Always clean the MAF and replace the PCV before spending on sensors or injectors.