Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
The car's computer thinks the fuel injector for cylinder 4 is not closing properly, which means too much fuel might be getting into the engine.
The engine control module (ECM) has detected that the fuel injector on cylinder 4 is not closing as it should, leading to an imbalance in the air-fuel mixture.
The P301D code indicates that the ECM has identified an issue with the fuel injector on cylinder 4. Specifically, the injector is stuck in the open position, allowing an excessive amount of fuel to enter the combustion chamber. This can lead to poor engine performance, increased emissions, and potential damage to the catalytic converter due to unburned fuel.
• Rough idling
• Decreased fuel efficiency
• Check Engine Light illuminated
• Faulty fuel injector
• Wiring issues such as shorts or open circuits
• ECM malfunction
ECM: Engine Control Module, the computer that manages engine functions.
Fuel Injector: A component that sprays fuel into the engine's combustion chamber.
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for cylinder 4's injector.
• Test the injector for proper operation and electrical resistance.
• Replace the faulty injector.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Fuel injector puller
$200 - $500
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regularly clean fuel injectors.
• Use high-quality fuel.
• Perform routine engine maintenance.
Engine Performance
• Avoid driving the vehicle for extended periods with this issue.
• Consult a professional mechanic for accurate diagnosis and repair.
Check vehicle warranty for coverage on fuel system components.
This code has been more prevalent in vehicles with higher mileage or those that have not received regular maintenance.
Moderate – Addressing this issue promptly can prevent further engine damage.
Continuing to drive with this issue may lead to increased emissions and potential legal issues in areas with strict emission standards.
• Engine running
• Vehicle at operating temperature
The fuel injector for cylinder 4 is located on the engine, typically near the intake manifold.
Q: Can I drive with a P301D code?
A: It's not recommended to drive for long periods with this code, as it can lead to engine damage.
Q: How can I prevent injector issues?
A: Regular maintenance and using high-quality fuel can help prevent injector problems.
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Universal · Digital multimeter
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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
Relevant when catalyst-efficiency or emissions faults persist after proper diagnosis.
Catalyst-efficiency faults sometimes point toward converter problems after proper testing.
Catalytic converters are highly vehicle-specific and should not be purchased by code alone.
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.