Fuel and air code
P0172: Engine getting too much fuel (bank 1)
How much to fix P0172? Typically $170–$820.
Wide range: this job varies a lot. Itemize your quote for a better answer.
How this range is built
| Part of the job | Low | High |
|---|---|---|
| Parts | $50 | $260 |
| Labor: 1 to 3.5 hours × $110 to $150 an hour | $110 | $525 |
| Fees: shop supplies, disposal, diagnostics | $10 | $30 |
| Total, rounded | $170 | $820 |
The hourly rate is the BLS Occupational Employment and Wage Statistics, May 2025 average pay for this trade in the US, $27.13 an hour, times 4 to 5.5 to cover what a shop bills (overhead, tools, insurance, profit). Parts are a band from budget aftermarket to the manufacturer part. Full method.
Not a repair shop, estimates only. Typical range, estimate. Not a quote. Your car, parts and shop change the number.
This is the range for the most common fix, fuel injector replacement (one injector). Which repair your car needs depends on a proper diagnosis.
The oxygen sensors on the side of the engine with cylinder 1 are reporting too much fuel for the amount of air. The computer is already trimming fuel back as far as it can and the mix is still too rich, which wastes gas and can overheat the catalytic converter over time.
- Safe to drive?
- Usually yes, for now
- Most common cause
- Leaking or stuck-open fuel injector
Safe for short trips, but a rich engine wastes gas and can foul the converter, so get it looked at soon.
Get quotes from local shops
Got P0172? Tell us your ZIP and a shop near you can quote the repair. Free, takes a minute.
Fair Price is not a contractor or a repair shop. Who sees your request
What you may notice
- Black smoke or fuel smell from the tailpipe
- Poor mileage
- Rough idle
Common causes, most likely first
- Leaking or stuck-open fuel injector
- Dirty or failing mass airflow sensor
- Bad oxygen sensor
- Clogged air filter
- High fuel pressure from a bad regulator
Check this first
Check the engine air filter and look for a fuel smell in the oil. Ask the shop to check fuel pressure and look at the fuel trim numbers.
Other repairs that sometimes fix P0172
| Repair | Typical range, US |
|---|---|
| Mass airflow sensor replacement | $120 to $390 |
| Oxygen sensor replacement (one sensor) | $100 to $350 |
| Diagnostic scan (check engine light) | $55 to $250 |
Before you pay
- Ask the shop what test showed this part is the cause, not just that the code appeared.
- Ask for parts and labor listed separately, and for the hours.
- Ask for a written OK before any extra work. Many states require written authorization before repairs.
Got a quote already? Check it against the range. Want to see if your car has a recall tied to this problem? Check recalls by VIN.
Need to read a code yourself? OBD-II scanners on eBay (affiliate link, disclosure).
P0172 questions
Can a dirty air filter set this code?
It can, when it is badly clogged and starving the engine of air. A new filter is cheap, so it is an easy thing to rule out first. If the filter is already clean, the cause lies elsewhere.
Is a rich engine bad for the catalytic converter?
Yes, over a long time. Unburned fuel overheats and coats the converter, which can ruin it. So do not let a rich code sit for months. Addressing it early costs far less than a new converter.
Can oil smell like gasoline with this?
Yes. A leaking injector can wash fuel into the crankcase and thin the oil. If the oil smells like gasoline or the dipstick reads over full, change the oil soon and ask the shop to test the injectors.
How much does it cost to fix P0172?
The most common fix, fuel injector replacement (one injector), has a typical range of $170 to $820 across the US. It is an estimate built from parts prices and local labor wages, not a quote. Your car and shop change it.
Typical range in 10 metro areas
Only the labor rate changes between cities. Same parts, same hours.
| Area | Typical range, estimate |
|---|---|
| Boston area, Massachusetts | $180 to $910 |
| New York City area | $180 to $870 |
| Los Angeles area, California | $180 to $890 |
| Chicago area, Illinois | $170 to $840 |
| Houston area, Texas | $160 to $800 |
| Dallas-Fort Worth area, Texas | $160 to $800 |
| Phoenix area, Arizona | $170 to $820 |
| Atlanta area, Georgia | $170 to $840 |
| Miami area, Florida | $160 to $820 |
| Seattle area, Washington | $180 to $890 |
Related codes
- P0175: Engine getting too much fuel (bank 2)
- P0171: Engine getting too much air or too little fuel (bank 1)
- P0101: Air flow sensor reading seems off
- P0300: Random or multiple cylinder misfires
More fuel and air codes
Code meaning written in our own words. Some codes mean different things on different makes, so check your scan tool or manual. Not a repair shop, estimates only.