Cylinder 3 Injector Circuit Low
P0267 indicates that the fuel injector circuit for cylinder 3 is operating at a lower voltage or current than expected. This causes an improper fuel spray pattern to that cylinder, resulting in a lean fuel mixture that triggers the oxygen sensor to signal the PCM, which then over-compensates by richening the entire engine's fuel mixture.
What You Might Notice
- Check engine light illuminated with P0267 code stored
- Engine running rough or misfiring
- Noticeable loss of power and acceleration
- Significant drop in fuel economy
- Possible cylinder 3 misfire condition
Most Common Causes
- 1
Dirty or clogged fuel injector
Carbon buildup on the injector nozzle reduces spray pattern quality and fuel delivery to cylinder 3. This is the most common cause and often resolved by cleaning or replacing the injector.
- 2
Faulty fuel injector electrical circuit
A broken wire, poor connector contact, or internal injector coil failure prevents proper voltage from reaching the injector, causing it to fire weakly or not at all.
- 3
PCM or fuel injector driver module failure
The engine control module's fuel injector output circuit may be damaged or failing, preventing it from delivering adequate voltage to the cylinder 3 injector.
- 4
Low fuel pressure or weak fuel pump
Insufficient fuel system pressure affects all injectors but may be more noticeable on cylinder 3 if combined with a slightly restricted injector.
How to Diagnose It
- 1
Check Dirty or clogged fuel injector — Carbon buildup on the injector nozzle reduces spray pattern quality and fuel delivery to cylinder 3. This is the most common cause and often resolved by cleaning or replacing the injector.
- 2
Check Faulty fuel injector electrical circuit — A broken wire, poor connector contact, or internal injector coil failure prevents proper voltage from reaching the injector, causing it to fire weakly or not at all.
- 3
Check PCM or fuel injector driver module failure — The engine control module's fuel injector output circuit may be damaged or failing, preventing it from delivering adequate voltage to the cylinder 3 injector.
- 4
Check Low fuel pressure or weak fuel pump — Insufficient fuel system pressure affects all injectors but may be more noticeable on cylinder 3 if combined with a slightly restricted injector.
How to Fix It
- 1
Clean or replace fuel injector
Remove the fuel injector for cylinder 3 and either have it professionally cleaned using ultrasonic cleaning or replace it with a new unit. Ensure fuel rail pressure is within spec before reinstalling.
- 2
Inspect and repair fuel injector electrical connections
Check the connector and wiring harness for cylinder 3 fuel injector for corrosion, loose pins, or damage. Clean connector contacts and repair or replace damaged wiring as needed.
- 3
Test fuel system pressure and replace fuel pump if needed
Use a fuel pressure gauge to verify the fuel pump is delivering adequate pressure to the fuel rail. If pressure is low, the fuel pump may need replacement.
- 4
Diagnose and repair PCM or injector driver circuit
If cleaning the injector and checking wiring does not resolve the code, the PCM's fuel injector driver circuit or a separate fuel injector control module may be defective and require professional diagnosis and possible replacement.
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