P0175
Moderate severitySystem Too Rich (Bank 2)
A P0175 rarely leaves you stranded, but an engine running rich wastes fuel, fouls spark plugs and can overheat the catalytic converter over time. Plan to get it diagnosed within a week or two — sooner if fuel economy has dropped sharply.
Stop driving if: you smell raw fuel, see black smoke from the exhaust, or the check engine light starts flashing.
What does the P0175 code mean?
The P0175 code means your engine computer has detected that Bank 2 is running too rich — there’s too much fuel for the amount of air coming in. The computer has been pulling fuel out to compensate (this is called “fuel trim”), and it has reached the limit of how much it can correct.
“Bank 2” is the side of the engine that does not contain cylinder number 1, so you’ll only see P0175 on V6, V8 and other engines with two cylinder banks. It’s the Bank 2 twin of P0172. If both codes show up together, the cause is almost always something both banks share — like the mass air flow sensor or fuel pressure.
Can you keep driving with a P0175 code?
In most cases, yes — at least in the short term. You may notice worse fuel economy, a fuel smell, a rough idle or black smoke. The longer you drive rich, the more you risk fouled spark plugs, misfires and, eventually, a damaged catalytic converter — so don’t leave it for months.
If the check engine light starts flashing, the engine is misfiring badly enough to damage the converter. Pull over and stop driving.
What causes a P0175 code?
Listed in the order most shops would check them — cheapest and most likely first, not as statistical odds. The real cause varies by year, make, model and engine.
- Dirty or clogged engine air filterCheck 1st
- Dirty or faulty mass air flow (MAF) sensorCheck 2nd
- Faulty Bank 2 oxygen sensor or coolant temperature sensorCheck 3rd
- Leaking fuel injector or excessive fuel pressureCheck last
How to diagnose a P0175 (check these first)
Rule out the cheap causes first, in this order:
- Scan for other codes. P0172 alongside P0175 points to a shared cause (MAF, fuel pressure, coolant sensor); P0175 alone points to something on Bank 2 only.
- Check the engine air filter. A badly clogged filter restricts airflow and can push the mixture rich.
- Clean the MAF sensor with dedicated MAF cleaner spray — never touch the sensing wires. A dirty MAF misreads airflow and is a very common cause.
- Look at live data: compare long-term fuel trims on both banks and check the coolant temperature reading. An engine that “thinks” it is cold will add extra fuel.
- If it still runs rich, have the fuel pressure tested and the Bank 2 injectors checked for leaks.
P0175 repair cost
Costs vary a lot by vehicle and region. These are typical US ranges including parts and labor — treat them as a ballpark for the conversation with your shop, not a quote.
| Engine air filter | $20 – $60 |
| MAF sensor cleaning | $10 – $100 |
| MAF sensor replacement | $150 – $400 |
| Oxygen (O2) sensor replacement | $150 – $350 |
| Fuel injector replacement | $200 – $600 |
| Fuel pressure regulator | $150 – $450 |
Tools & parts that help
A scanner that shows live fuel trims tells you whether the problem is on one bank or both — the single most useful clue for a rich code. A can of MAF sensor cleaner is a cheap first fix worth trying before replacing any parts.
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P0175 — Frequently asked questions
Is it safe to drive with a P0175 code?
Usually yes, in the short term. But running rich wastes fuel and can damage the catalytic converter over time, so get it checked within a week or two. If the light is flashing, stop driving.
What’s the difference between P0172 and P0175?
Both mean the engine is running too rich. P0172 is Bank 1, the side with cylinder 1. P0175 is Bank 2, the other side. Both together usually means a shared cause like the MAF sensor or fuel pressure.
Can a dirty air filter cause P0175?
Yes. A badly clogged filter restricts airflow, which can make the mixture rich. It is the cheapest thing to check first.
How much does it cost to fix a P0175?
Anywhere from about $20 for an air filter or $10 for MAF cleaner up to $600 for a fuel injector, depending on the real cause and your vehicle.
Related codes
General guidance based on the standard SAE definition of the P0175 code. A real diagnosis depends on your make, model, year, engine and other symptoms. This is not a substitute for a professional inspection — when in doubt, have a technician confirm the cause before replacing expensive parts.