What Does P02C4 Mean?
The ECM has determined that the fuel injector on cylinder 11 is restricted, meaning it cannot deliver the commanded amount of fuel. The PCM detects this through individual cylinder fuel trim data showing the injector needs more on-time than normal to achieve target fueling. The driver may notice misfires, rough running, or reduced power especially at higher RPM and load where fuel demand is greatest.
Common Causes
40%
Carbon or varnish deposits clogging the injector spray orifices on cylinder 11
25%
Contaminated fuel or debris in the fuel system blocking the injector inlet screen
15%
Damaged or deformed injector pintle not opening fully
12%
Low fuel rail pressure reducing effective injector flow rate
8%
Wiring or connector issue reducing voltage/current to the injector solenoid
Diagnostic Steps
1
Compare cylinder 11 fuel trim to other cylinders via live data — a significantly higher positive trim on cylinder 11 confirms restricted flow.
2
Perform an injector flow bench test if possible, or use a Noid light to verify the injector is receiving proper electrical pulses from the ECM.
3
Check fuel rail pressure with a mechanical gauge — verify it meets manufacturer specification under load; low pressure affects all cylinders but worsens a restricted one.
4
Remove the cylinder 11 injector and inspect the tip for visible carbon deposits or debris blockage; compare spray pattern against a known-good injector if equipment allows.
5
Attempt professional ultrasonic injector cleaning — if flow does not improve to within 5% of specification, replacement is required.
Estimated Repair Cost
$150 - $800
Parts + labor, varies by vehicle and location
The ECM has determined that the fuel injector on cylinder 11 is restricted, meaning it cannot deliver the commanded amount of fuel. The PCM detects this through individual cylinder fuel trim data showing the injector needs more on-time than normal to achieve target fueling. The driver may notice mis...
The most common cause of P02C4 (Cylinder 11 - Injector Restricted) is: Carbon or varnish deposits clogging the injector spray orifices on cylinder 11
Typical repair costs for P02C4 range from $150 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The vehicle can be driven carefully, but the lean condition in cylinder 11 may cause misfires and potential catalytic converter overheating. Avoid heavy acceleration and have the injector serviced or replaced promptly.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P02C4 to identify the root cause.
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Quick Info
Category
Powertrain
System
Fuel System
Difficulty
Type
Generic (SAE)
Recommended Tools
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