Jan 13, 2026 · How to fix a P0303 code quickly and efficiently by addressing spark plugs, ignition coils, and more—discover the essential steps you need to take.

Learn what the P0303 diagnostic trouble code means and how to troubleshoot a misfire in cylinder 3 of your engine with AutoZone.

May 30, 2025 · The P0303 code indicates your 3 cylinder is misfiring. A misfire occurs when one of the cylinders inside of your engine doesn’t fire because something is off in the fuel-air-spark ratio.

Aug 25, 2024 · The P0303 code means that cylinder 3 is misfiring or is randomly misfiring. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on …

Jan 1, 2026 · The P0303 trouble code indicates that the vehicle’s engine control module (ECM) has detected a misfire occurring specifically within the third cylinder of the engine. A misfire happens …

Jul 8, 2025 · What is the P0303 Code for a Cylinder 3 Misfire? The P0303 code is a diagnostic trouble code (DTC) that means a cylinder 3 misfire detected by your electronic control module (ECM) has …

This guide explains the P0303 code’s meaning, symptoms, causes, and step-by-step diagnostics to fix it like a pro—potentially saving you $500-$800 from overpriced cylinder misfire repairs.

Oct 30, 2024 · Here's everything you need to know if your engine is showing the P0303 error code, which indicates that the engine control module has identified a misfire in cylinder 3. Here are the …

Jan 1, 2026 · The P0303 code means cylinder number 3 in your engine is not firing properly, which causes shaking and power loss. Is your check engine light on and your car shaking? A rough running …

Jan 18, 2025 · What does the P0303 Cylinder-3 Misfire Detected mean? P0303 code gets triggered when the Engine Control Module detects an engine misfire on cylinder-3. Misfire means that the …