P23F3 code meaning
Cylinder 2 Injector B Air-Fuel Ratio Imbalance
Powertrain system Generic code P23xx codes Check engine light
What P23F3 means
P23F3 points to cylinder 2 and to its injector B, the second of two injectors feeding that cylinder. The smallest engines able to raise it have three cylinders, for example Ford's 1.5 EcoBoost, which pairs port and direct injection and can switch one cylinder off at light load. On V engines the bank that holds cylinder 2 depends on how the maker numbers its cylinders, so read the service information before working on a side. Hyundai's Smartstream 1.0 and 1.2 MPi engines show that both injectors of a cylinder may also sit in the intake port; whether such a design calls one of them B is not published. No public document ties P23F3 to a vehicle. Compare with P219D for the same cylinder and with P21D0 for the injector B circuit.
P23F3 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 4 hours
- Clears after repairAfter a drive cycle
Symptoms of P23F3
- Check engine light on
- Shaking at idle, most noticeable on small three- or four-cylinder engines
- Slightly higher fuel consumption
Common causes of P23F3
- Most likelyInjector B of cylinder 2 delivering too much or too little fuel
- PossibleAir leak at the intake port or injector seal of cylinder 2
- PossibleWork done on the wrong cylinder because of the maker's numbering scheme
- Less likelyChafed wire to injector B of cylinder 2 (check P21D0)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel injector b cyl 2
What each part of P23F3 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 3 | Area: ignition system or misfire. |
| F3 | The exact fault in that area. |
What to do next
- Note P23F3 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P23F3
What does P23F3 mean?
P23F3 means "Cylinder 2 Injector B Air-Fuel Ratio Imbalance". P23F3 points to cylinder 2 and to its injector B, the second of two injectors feeding that cylinder. It is a generic code, so it means the same on every make.
Is it safe to drive with P23F3?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P23F3 fail an emissions test?
Yes, it can. P23F3 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P23F3 to fix?
Difficulty: medium. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P23F3 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.