P0203 Code: Injector Circuit Malfunction - Cylinder 3
🟠 Moderate severity · drivable
Drivable, but cylinder 3 may misfire and the engine will run rough. Fix it soon.
What P0203 means
The fuel injector circuit for cylinder 3 has an electrical fault, so cylinder 3 isn't getting the right amount of fuel.
Symptoms
- Check engine light on (may flash)
- Rough idle or misfire
- Loss of power
- Poor fuel economy
Common causes
- most common: Faulty fuel injector on cylinder 3
- common: Damaged wiring or loose connector at the injector
- less common: Injector driver fault in the engine computer
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Inspect and clean the injector connector | Yes | $0–10 |
| Replace the cylinder 3 fuel injector | Mechanic | $100–300 |
| Repair damaged injector wiring | Mechanic | $50–150 |
Frequently asked questions
Can I drive with a P0203 code?
Yes, but cylinder 3 may misfire and the engine will run rough. Fix it soon.
What is the most common cause of P0203?
A faulty fuel injector or a wiring/connector problem at the cylinder 3 injector.
How much does it cost to fix a P0203?
Typically $100–$300 for a new fuel injector, or less for a wiring repair.
Related codes
P0303
P0303 Code: Cylinder 3 Misfire Detected
P0202P0202 Code: Injector Circuit Malfunction - Cylinder 2
P0204P0204 Code: Injector Circuit Malfunction - Cylinder 4
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.