P21B8
Cold Start Cylinder 3 Injection Timing
P21B8 is an OBD-II diagnostic trouble code meaning: Cold Start Cylinder 3 Injection Timing. Common causes: malfunction of the fuel injector of cylinder 3, problems with the fuel pump or pressure regulator. Estimated repair cost: $17–89.
Symptoms
- Unstable engine operation at idle
- Increased fuel consumption
- Difficulty starting the engine, especially in cold weather
- Loss of engine power
- Increased emissions of harmful substances
Causes
- Malfunction of the fuel injector of cylinder 3
- Problems with the fuel pump or pressure regulator
- Contaminated or damaged fuel lines
- Malfunction of sensors affecting injection (mass air flow sensor, coolant temperature sensor)
- Problems with the engine control unit (ECU)
How to Fix
- Check the condition and operation of the fuel injector of cylinder 3
- Check the pressure in the fuel system
- Clean or replace fuel filters
- Check the operation of sensors that affect fuel injection
- Scan the ECU for other errors
Related codes
Error P21B8 by Vehicle Brand
FAQ
What does the P21B8 code mean?
P21B8 is an OBD-II diagnostic trouble code that indicates: Cold Start Cylinder 3 Injection Timing
What causes a P21B8 error code?
The most common causes of P21B8 include: Malfunction of the fuel injector of cylinder 3; Problems with the fuel pump or pressure regulator; Contaminated or damaged fuel lines; Malfunction of sensors affecting injection (mass air flow sensor, coolant temperature sensor).
How do I fix a P21B8 diagnostic trouble code?
To fix P21B8: Check the condition and operation of the fuel injector of cylinder 3. Check the pressure in the fuel system. Clean or replace fuel filters. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P21B8?
Yes, but get it checked soon
How much does it cost to fix P21B8?
The estimated repair cost for P21B8 is $17–89. Actual cost depends on your vehicle, location, and labor rates.
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