<h2>Direct-Fit Ignition Coil and Iridium Spark Plug Kit for 2004-2005 Mazda 3</h2> <p><strong>Restores primary ignition health:</strong> A direct-replacement 4-cylinder tune-up kit engineered to resolve secondary voltage breakdown, intermittent misfires, and rough idle on the 2.0L MZR engine.</p> <h3>The Stock Mazda 3 Ignition Breakdown</h3> <p>With age and continuous heat cycling in the cylinder head wells, factory coil-on-plug assemblies suffer internal dielectric degradation and epoxy breakdown. This thermal stress causes micro-arcing, weakened secondary spark output, and unburnt fuel cycles. Concurrently, factory standard plugs wear at the ground electrode, expanding the plug gap and forcing degraded coils to exceed their voltage capacity under acceleration load.</p> <h3>The Engineering Solution</h3> <p>This kit matches heavy-duty coil packs with fine-wire iridium spark plugs. The coil assemblies utilize dense-wound copper primary and secondary windings potted in high-dielectric epoxy to resist thermal breakdown and eliminate voltage leakage. Paired with corrosion-resistant iridium center electrodes requiring lower strike voltage, this setup ensures rapid flame kernel propagation, crisper throttle response, and stable combustion under high engine load.</p> <h3>Technical Specifications</h3> <table width="100%" style="border-collapse: collapse; border: 1px solid #e0e0e0; font-size: 14px;"> <tr style="background-color: #f9f9f9;"> <td style="padding:8px;"><strong>Fitment</strong></td> <td style="padding:8px;">2004-2005 Mazda 3</td> </tr> <tr> <td style="padding:8px;"><strong>Engine / Chassis</strong></td> <td style="padding:8px;">2.0L MZR (LF-DE) / BK Chassis</td> </tr> <tr style="background-color: #f9f9f9;"> <td style="padding:8px;"><strong>Stock Output</strong></td> <td style="padding:8px;">148 hp / 135 lb-ft (Approx)</td> </tr> <tr> <td style="padding:8px;"><strong>Part Number</strong></td> <td style="padding:8px;">DG541, DG507, FD505, UF621</td> </tr> </table> <h3>Compatibility</h3> <ul> <li>2004 Mazda 3 i Sedan 2.0L L4 Gas</li> <li>2005 Mazda 3 i Sedan 2.0L L4 Gas</li> <li>2004 Mazda 3 2.0L 4-Cylinder Models</li> <li>2005 Mazda 3 2.0L 4-Cylinder Models</li> </ul> <h3>The Mazda Driving Caliber</h3> <p>Engineered to meet stringent Japanese OEM ignition tolerances, this kit restores crisp throttle modulation, eliminates low-RPM hesitations, and ensures reliable cold starts without throwing check engine lights.</p>