Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This means that a sensor in your car is telling the computer that there's too much pressure in the system that stops gas fumes from escaping.
The P11C6 code indicates that the signal from the EVAP system differential pressure sensor is higher than expected, suggesting an issue with the sensor or the circuit.
The EVAP system differential pressure sensor measures the pressure difference in the evaporative emission control system. A 'high' circuit signal typically means the sensor is sending a voltage signal that is higher than the predetermined threshold set by the vehicle's manufacturer, which could be due to a malfunctioning sensor, wiring issues, or an actual pressure problem within the EVAP system.
• Check Engine Light illuminated
• Possible fuel odor
• Failed emissions test
• Faulty EVAP differential pressure sensor
• Wiring issues or poor connections in the sensor circuit
• Actual high pressure within the EVAP system
EVAP: Evaporative Emission Control System
OBD-II: On-Board Diagnostics, Second Generation
• Use an OBD-II scanner to confirm the code.
• Inspect the EVAP differential pressure sensor and its wiring for damage.
• Measure the voltage and resistance in the sensor circuit to check for abnormalities.
• Replace the EVAP differential pressure sensor if faulty.
• Repair or replace damaged wiring or connectors.
• Ensure the EVAP system is not over-pressurized.
• OBD-II scanner
• Multimeter
• Wrench set
$100 - $300
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regularly inspect and maintain the EVAP system.
• Ensure gas cap is tightly secured after refueling.
• Check for recalls related to the EVAP system.
Sensor Issue
• Avoid overfilling the gas tank.
• Get regular vehicle check-ups to catch issues early.
Check with the manufacturer as emissions-related components may be covered under warranty.
This code is less common but can occur in vehicles with aging EVAP systems or those with manufacturing defects.
Moderate – While not immediately dangerous, it should be addressed to prevent further emissions issues.
Driving with a malfunctioning EVAP system may lead to increased emissions, which could be illegal depending on local regulations.
• Vehicle at operating temperature
• EVAP system under normal pressure conditions
The EVAP differential pressure sensor is typically located near the fuel tank or along the EVAP lines.
Q: Can I still drive my car with a P11C6 code?
A: Yes, but it's best to get it checked soon to avoid emissions issues.
Q: Will a loose gas cap cause a P11C6 code?
A: Not directly, but it can cause similar EVAP system issues.
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A wired color-screen reader with readiness hotkeys, live data, code definitions, and data logging.
Good for emissions-related codes because it exposes readiness monitors and live powertrain data.
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Specialty · Smoke machine
Helpful for finding EVAP and vacuum leaks that are hard to see with visual inspection alone.
Helpful for tracking down EVAP and vacuum leaks that can trigger emissions faults.
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Specialty · O2 sensor socket
Helpful when the code points toward exhaust or oxygen-sensor work and space is tight.
Useful when the diagnosis points toward oxygen-sensor removal or replacement.
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Fitment Required · Vehicle-fitment part
Relevant when EVAP diagnosis points toward purge-flow or purge-control faults.
EVAP diagnosis often includes purge-flow and valve-control faults.
Confirm the failed valve and exact fitment before buying parts.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.