A P0303 code on your 2018 Ford F-150 indicates that the engine control module has detected cylinder 3 misfires beyond acceptable parameters. This 13th generation F-150 offers multiple proven engine options.
2018 F-150 Engine Options
The 2018 Ford F-150 offered several engines: 3.5L EcoBoost, 2.7L EcoBoost, 5.0L Coyote V8, and 3.3L V6. The EcoBoost engines use turbocharging while the V8 is naturally aspirated.
Higher Mileage Considerations
2018 F-150s have accumulated significant mileage by now. Normal wear items including spark plugs and ignition coils may need replacement. EcoBoost engines may benefit from carbon cleaning.
EcoBoost Carbon Buildup
Direct injection EcoBoost engines can develop carbon deposits on intake valves over time. This affects airflow and can contribute to misfires. Consider inspection if other causes are ruled out.
5.0L V8 Analysis
The Coyote V8 uses dual fuel injection (port and direct) to help prevent carbon buildup. This design offers the best of both technologies.
Proven Platform
The 13th generation F-150 has proven reliable. Address misfires to maintain dependable truck operation.