Cylinder 8 Injector Restricted
The P02B8 code indicates that the engine control module (ECM) has detected a restriction in the fuel injector for cylinder 8. This means the injector is not delivering the proper amount of fuel, often due to clogging or internal damage. The ECM monitors fuel trim and injector performance; when cylinder 8 deviates significantly, it sets this code. A restricted injector can cause lean misfires, reduced power, and increased emissions.
1. Most Common Causes
- Clogged or partially blocked fuel injector on cylinder 8
- Internal mechanical injector failure (stuck valve, faulty coil)
- Clogged fuel filter restricting flow
- Fuel pump delivering insufficient pressure
- Fuel contamination (water, sediment, excessive ethanol)
- Carbon deposit buildup on the injector tip
- Injector wiring with high resistance or poor connection
- Intermittent injector driver failure in the ECM/PCM
2. Symptoms You Will Notice
- Check Engine Light on
- Engine misfire or rough idle
- Reduced power and acceleration
- Poor fuel economy
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Perform a fuel injector balance test to compare cylinder 8 to others.
Step 3: Inspect injector wiring and connector for damage or corrosion.
Step 4: Check fuel pressure and quality; replace fuel filter if needed.
Step 5: If injector is confirmed restricted, replace it.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as a restricted injector can cause misfires, catalytic converter damage, and poor performance. Have it diagnosed promptly.
How much does it cost to fix?▼
Replacing a single fuel injector typically costs $50-$150 for parts and labor, but diagnostic fees may add $50-$100.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.