P21B8

Cold Start Cylinder 3 Injection Timing

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$17–89 (est.)

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

P21B7 P21B9 P21BA