P0175 means the engine control module has detected the air-fuel mixture on Bank 2 running consistently too rich — the exact Bank 2 counterpart to P0172, and together with P0171 and P0174, completes the full set of four fuel trim codes covering both lean and rich conditions on both cylinder banks of a V-configuration engine. As with all Bank 2 codes on this site, this only applies to V6, V8, and similar engines with two separate cylinder banks — an inline engine has only one bank and can’t produce a Bank 2 code at all.
What Does P0175 Mean?
This code fires under the identical logic to P0172, just monitoring Bank 2 of a V-configuration engine instead of Bank 1. The engine control module has had to command a persistently richer-than-normal fuel correction on that bank specifically to compensate for an actual mixture running rich, and that correction has exceeded its normal expected range. See our P0172 guide for the fuller explanation of what “rich” means and how it differs from a lean condition — the concepts and diagnostic approach transfer directly, just applied to the other bank.
Common Symptoms
- Check engine light on
- Reduced fuel economy
- A rough idle or occasional hesitation
- A sooty or fuel-like smell from the exhaust
- Black exhaust smoke in more severe cases
Common Causes, Most Likely First
- A failing mass airflow (MAF) sensor, the same leading cause as P0172, over-reporting actual air intake.
- A leaking or stuck-open fuel injector specific to a cylinder on Bank 2.
- A failing fuel pressure regulator, affecting the whole fuel system rather than one bank specifically, though it can sometimes manifest more strongly on one bank’s oxygen sensor reading.
- A restricted air intake, from a clogged filter or collapsed ducting.
- A failing oxygen sensor on Bank 2, giving an inaccurate rich reading independent of the actual mixture.
How to Diagnose It
- Confirm which bank is Bank 2 on your specific engine, since manufacturer conventions vary — a repair manual or VIN-based lookup will clarify this.
- Check the engine air filter and MAF sensor — see our engine air filter guide — since these affect the whole engine, not just one bank.
- Check live fuel trim data separately for both banks with an OBD-II scanner — see our OBD-II scanner guide — to see whether the rich condition is isolated to Bank 2 specifically or present on both banks (which would point more toward a shared cause like the air filter or MAF sensor).
- If Bank 2 alone shows the issue, focus on that bank’s specific injectors and oxygen sensor.
Never work under a vehicle supported only by a jack. Use axle stands on firm, level ground, chock the wheels that stay down, and leave the car in gear or Park with the handbrake on. A jack lifts; stands hold.
Possible Fixes
| Cause | Fix | Typical cost |
|---|---|---|
| Dirty/clogged air filter | Replace the air filter | $15 – $60 |
| Dirty MAF sensor | Clean or replace the MAF sensor | $50 – $250 |
| Leaking fuel injector (Bank 2) | Clean or replace the injector | $150 – $400 |
| Failing fuel pressure regulator | Replace the regulator | $150 – $350 |
Can I Keep Driving With This?
Short trips only, and address it reasonably soon — the same urgency guidance as P0172 applies here: a persistently rich mixture wastes fuel and risks fouling spark plugs or damaging the catalytic converter if ignored for too long.
When to See a Mechanic
Reasonably soon rather than urgently — check the air filter and MAF sensor yourself first. More in our trouble codes section.
Frequently Asked Questions
What does P0175 mean?
It means the air-fuel mixture on Bank 2 is running consistently too rich — the Bank 2 counterpart to P0172, applying only to V-configuration engines with two cylinder banks.
What’s the difference between P0175 and P0172?
They’re the identical fault on different cylinder banks — P0172 is Bank 1, P0175 is Bank 2. Only V6, V8, and similar engines with two banks can produce both codes.
Does every engine have a Bank 2?
No — only V-configuration engines (V6, V8, etc.) have two separate cylinder banks. An inline engine has only one bank and would never produce a Bank 2 code.
Is it safe to drive with a P0175 code?
Short trips only — get it addressed reasonably soon, since a persistently rich mixture can damage the catalytic converter or foul spark plugs over time.
How much does it cost to fix P0175?
Often $15–$60 for an air filter, up to $250 for a MAF sensor, or up to $400 if a fuel injector on Bank 2 needs attention.
