System Too Rich (Bank 2)
In short
P0175 means the engine computer detected that the air-fuel mixture on Bank 2 (the cylinder bank not containing cylinder #1 on most V6/V8 engines) has too much fuel relative to air, and the system can no longer trim it back to normal. The most common real-world cause is a dirty or failing mass airflow (MAF) sensor that over-reports incoming air, though a leaking fuel injector, high fuel pressure, or a contaminated oxygen sensor are also frequent culprits.
Is it safe to drive with P0175?
It is usually safe to drive short-term, but a persistently rich mixture wastes fuel and can foul spark plugs and overheat the catalytic converter over time. If you smell raw fuel, see black smoke, or notice rough running, limit driving and fix it promptly to avoid catalytic converter damage.
Symptoms
- Illuminated check engine light
- Reduced fuel economy / more frequent fill-ups
- Black or sooty smoke from the tailpipe
- Strong fuel smell from the exhaust
- Rough idle, hesitation, or occasional stalling
- Fouled spark plugs or failed emissions test
Common causes (most → least likely)
How to diagnose it (before buying parts)
- 1 Scan for all stored codes and freeze-frame data; note whether P0174 (lean) or other bank-specific codes are present, since combined codes point toward a shared cause like the MAF.
- 2 View live data and check long-term and short-term fuel trims on Bank 2 — strongly negative trims (e.g., -15% or more) confirm the PCM is pulling fuel out to compensate for a rich condition.
- 3 Inspect the MAF sensor for oil/dirt contamination and check live MAF airflow (g/s) at idle against spec; gently clean the element with MAF-specific cleaner and re-test.
- 4 Measure fuel pressure with a gauge and compare to spec; watch for pressure that is too high or that does not drop when commanded, indicating a regulator or pump fault.
- 5 Check Bank 2 oxygen sensor response and inspect injectors for leakage (smell of fuel, wet plugs, or a balance/injector-leak test) before condemning any single part.
Repair options & cost
By manufacturer
On V6/V8 Fords, P0175 (often paired with P0174) is frequently traced to a dirty MAF sensor or degraded fuel injectors; Bank 2 is the passenger side on most transverse V6 layouts but verify per engine.
GM V8 trucks and SUVs commonly throw rich codes from contaminated MAF sensors and, on higher-mileage engines, leaking injectors or fuel pressure regulator issues.
On Chrysler/Dodge/Jeep V6 and V8 engines, rich codes are often linked to fuel pressure regulator faults or injectors, and occasionally a contaminated upstream O2 sensor.
On Toyota V6/V8 engines, a rich Bank 2 condition is frequently caused by a failing air-fuel ratio (wideband) sensor or MAF contamination rather than mechanical injector faults.
Frequently asked questions
Which side is Bank 2 on my engine?
Bank 2 is the side of the engine that does NOT contain cylinder number 1. On most transverse (sideways) V6 engines it is the bank closest to the firewall or the passenger side, but the exact location varies by engine, so confirm with your vehicle's firing-order or service information.
Can I drive with a P0175 code?
Short trips are generally fine, but driving for an extended period with a rich mixture can foul spark plugs, dump raw fuel into the exhaust, and overheat or damage the catalytic converter. Fix it soon, and avoid driving if you see black smoke or smell strong raw fuel.
Will cleaning the MAF sensor fix P0175?
It often helps when a contaminated MAF is the cause, and it is a cheap first step. Use a dedicated MAF sensor cleaner, never carb or brake cleaner, and re-check fuel trims afterward; if the rich condition returns, the sensor or another component likely needs replacement.
How much does it cost to fix P0175?
It ranges widely depending on the cause. A MAF cleaning may cost only the price of a can of cleaner, a MAF or O2 sensor replacement typically runs 120 to 450 dollars at a shop, while injector or fuel-pressure-regulator repairs can reach 700 dollars or more.