P23F2 code meaning
Cylinder 1 Injector B Air-Fuel Ratio Imbalance
Powertrain system Generic code P23xx codes Check engine light
What P23F2 means
P23F2 says that the mixture in cylinder 1 has drifted away from the other cylinders and that the control unit holds the second injector of that cylinder, injector B, responsible. Only engines that feed each cylinder through two injectors can produce it. Toyota first paired a port and a direct injector in each cylinder with D-4S on the 2005 2GR-FSE V6. Ford's 2024 OBD summary shows what the letter means there: the port injectors are checked as Fuel System B (circuit codes P21CF to P21D6), the direct injectors as system A. CARB makes an imbalance check mandatory and asks that the code name the cause as exactly as the method permits. No maker documents P23F2 itself; Ford and GM still report imbalance per bank. Cylinder 1 is by definition on bank 1, so read P219C and P0301 alongside.
P23F2 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 P23F2
- Check engine light on
- Often no noticeable drivability change
- Slightly rough idle or a misfire count on cylinder 1
Common causes of P23F2
- Most likelyInjector B (usually the port injector) of cylinder 1 clogged or dripping
- PossibleLeaking injector O-ring or intake runner gasket at cylinder 1
- Less likelyLoose connector on injector B of cylinder 1 (often with P21CF)
- Less likelyPoor valve sealing on cylinder 1
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 1
What each part of P23F2 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. |
| F2 | The exact fault in that area. |
What to do next
- Note P23F2 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 P23F2
What does P23F2 mean?
P23F2 means "Cylinder 1 Injector B Air-Fuel Ratio Imbalance". P23F2 says that the mixture in cylinder 1 has drifted away from the other cylinders and that the control unit holds the second injector of that cylinder, injector B, responsible. It is a generic code, so it means the same on every make.
Is it safe to drive with P23F2?
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 P23F2 fail an emissions test?
Yes, it can. P23F2 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 P23F2 to fix?
Difficulty: medium. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P23F2 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.