Fuel and air code
P0102: Air flow sensor signal too low
How this range is built
| Part of the job | Low | High |
|---|---|---|
| Parts | $70 | $250 |
| Labor: 0.5 to 0.8 hours × $125 to $175 an hour | $63 | $140 |
| Fees: shop supplies, disposal, diagnostics | $0 | $15 |
| Total, rounded | $130 | $410 |
The hourly rate is the BLS Occupational Employment and Wage Statistics, May 2025 average pay for this trade in Boston, $31.54 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, mass airflow sensor replacement. Which repair your car needs depends on a proper diagnosis.
The mass airflow sensor sits in the intake tube and reports how much air is going into the engine. The signal coming back is weaker than any normal running condition would produce, so the computer thinks almost no air is moving even though the engine is turning.
- Safe to drive?
- Usually yes, for now
- Most common cause
- Dirty or failing mass airflow sensor
Short trips are okay, but the car may idle roughly or stall; fix it soon.
What you may notice
- Rough idle
- Hard starting
- Stalling
- Weak acceleration
Common causes, most likely first
- Dirty or failing mass airflow sensor
- Loose or corroded sensor plug
- Broken wiring
- Air filter box leak or loose tube
- Blockage in the intake
Check this first
Unplug the airflow sensor, look for green or white buildup on the pins, and push it back in until the latch clicks. Also check the rubber air tube after the sensor for a loose clamp or crack.
Other repairs that sometimes fix P0102
| Repair | Typical range, Boston |
|---|---|
| Vacuum leak repair | $100 to $530 |
| Diagnostic scan (check engine light) | $60 to $290 |
| Throttle body cleaning | $85 to $210 |
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. Massachusetts rules 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).
P0102 questions
Could a loose plug cause this?
Yes. A plug that is only half seated can cut the signal to nothing. Reseating it takes seconds and costs nothing, so try it before spending money on a new sensor.
Is it the same as P0101?
No. P0102 means the sensor signal is lower than the lowest value that makes sense, which often points to a wire or plug problem. P0101 means the signal does not match what the engine is doing.
How long can I drive?
If the engine runs fine, you can drive a short time. Stop using the car if it stalls often or will not hold an idle, since a stall in traffic is the larger risk.
How much does it cost to fix P0102?
The most common fix, mass airflow sensor replacement, has a typical range of $130 to $410 in Boston. It is an estimate built from parts prices and local labor wages, not a quote. Your car and shop change it.
P0102 repair cost by city
Related codes
- P0101: Air flow sensor reading seems off
- P0103: Mass airflow sensor reads too high
- P1101: Airflow sensor out of expected range
- P0171: Engine getting too much air or too little fuel (bank 1)
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.