Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the computer in your car thinks there's too much electricity going to the fuel injector for cylinder 4. It's like if you were trying to water a plant with a fire hose instead of a gentle spray.
The P0271 code indicates that the fuel injector circuit for cylinder 4 is receiving higher than normal voltage.
This OBD-II code is set when the Engine Control Module (ECM) detects a high voltage condition in the fuel injector circuit for cylinder 4. This could be due to a wiring issue, a faulty injector, or a problem within the ECM itself.
• Check Engine Light on
• Engine misfire
• Poor fuel economy
• Faulty fuel injector
• Open or shorted injector wiring
• Faulty ECM
ECM: Engine Control Module
OBD-II: On-Board Diagnostics II
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for cylinder 4 injector.
• Test the fuel injector for proper operation.
• Repair or replace damaged wiring.
• Replace the faulty fuel injector.
• Replace or reprogram the ECM if necessary.
• OBD-II scanner
• Multimeter
• Fuel injector tester
$150 - $500
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regularly inspect and maintain fuel system components.
• Use quality fuel to prevent injector clogging.
• Keep electrical connections clean and secure.
Engine Performance
• Have a professional mechanic diagnose the issue.
• Avoid driving the vehicle until the problem is fixed to prevent further damage.
Check your vehicle's warranty for coverage on fuel injectors and ECM.
This code has been commonly reported in vehicles with high mileage or those that have experienced fuel system issues.
Moderate – It should be addressed soon to avoid engine performance issues.
Driving with a misfiring engine can lead to increased emissions and potential engine damage.
• Engine at operating temperature
• Vehicle in park or neutral
The fuel injector for cylinder 4 is located on the engine block, typically near the intake manifold.
Q: Can I drive my car with a P0271 code?
A: It's not recommended to drive with this code as it can lead to further engine damage.
Q: How do I reset the Check Engine Light after fixing the issue?
A: Use an OBD-II scanner to clear the code after repairs are completed.
High-End · Full-system diagnostics
A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.
Network faults often require full-system access instead of a generic code reader alone.
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Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
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Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
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Fitment Required · Vehicle-fitment part
Commonly relevant for misfire, ignition-efficiency, and some drivability-related repairs.
Misfire and ignition-related faults commonly involve spark plugs as part of the repair path.
Check the correct plug type, gap, and engine application for your vehicle.
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Fitment Required · Vehicle-fitment part
Relevant when the fault points toward ignition-coil performance or cylinder-specific ignition issues.
Some ignition faults involve coil performance or cylinder-specific coil problems.
Match the coil to your engine and confirm the failed component before ordering.
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.