P0201 and P0301 both stored -- which do I fix first?

They are linked. P0201 is the circuit fault causing the misfire that triggers P0301. Fix the injector circuit and P0301 should clear on its own.

Can I drive with a dead injector?

Briefly and carefully. A flashing check engine light means stop now. A steady light means limp to a shop. Running a cylinder on no fuel creates a damaging misfire.

Do I need to replace all injectors at once?

No, unless high mileage warrants it for preventive maintenance. Replacing the faulty one is the correct repair.

Codes › P0201

P0201: The fuel injector circuit for cylinder 1 has a fault

Injector Circuit Malfunction -- Cylinder 1

High severityCan you keep driving?

Drive with caution. A dead injector on cylinder 1 will cause a misfire. If the check engine light is flashing, stop driving. Raw fuel in the exhaust will damage the catalytic converter quickly.

What it means

P0201 means the PCM detected an electrical fault in the injector circuit for cylinder 1. This is a circuit code, not a flow code. It means the computer cannot confirm normal resistance or current when it commands the injector to fire. The cylinder may be misfiring as a result. The injector itself could be dead, or the wiring between the PCM and the injector could be open or shorted. A misfire code like P0301 often appears alongside P0201, which is the expected result of a cylinder that is not receiving fuel.

Common causes

Open or short in the injector wiring harnessHeat, chafing, and rodent damage are common. Check the harness before replacing the injector.
Failed fuel injectorThe injector solenoid coil has burned out. Resistance will be out of spec when measured with a multimeter.
Corroded or damaged injector connectorThe injector harness connector corrodes from engine heat and moisture over time.
Failed injector driver in the PCMRare, but the PCM output driver for the injector can fail. Usually only after other causes are ruled out.

What it costs

Wiring repair or connector replacement$80 to $250
Fuel injector replacement (single)$150 to $400 installed
PCM diagnosis and replacement$500 to $1,200

Symptoms

Check engine light on, steady or flashing
Rough idle and engine shake
Loss of power and hesitation
Possible P0301 (cylinder 1 misfire) stored alongside this code
Worse fuel economy

What to do next

Measure injector resistance with a multimeter at the injector connector. A healthy injector reads 10 to 18 ohms for most port injectors, and much lower (about 1 to 5 ohms) for direct injection. If resistance is out of spec, replace the injector. If resistance is fine, the fault is in the wiring or PCM driver. Swap injector connectors with an adjacent cylinder if possible to distinguish wiring from injector failure.

Lewis shows injector pulse width and misfires per cylinder so you can see in real time whether cylinder 1 is firing or completely dead. Download Lewis.

Related codes

FAQ

P0201 and P0301 both stored -- which do I fix first?: They are linked. P0201 is the circuit fault causing the misfire that triggers P0301. Fix the injector circuit and P0301 should clear on its own.
Can I drive with a dead injector?: Briefly and carefully. A flashing check engine light means stop now. A steady light means limp to a shop. Running a cylinder on no fuel creates a damaging misfire.
Do I need to replace all injectors at once?: No, unless high mileage warrants it for preventive maintenance. Replacing the faulty one is the correct repair.