P0303 Code: 2024 Lexus NX – What It Means & Cost to Fix

2024 Lexus NX P0303: Cylinder 3 Misfire Troubleshooting Guide

When your 2024 Lexus NX displays the P0303 code, the powertrain control module has identified consistent misfires in cylinder 3. The 2024 NX continues with refined versions of the turbocharged and hybrid powertrains.

2024 NX Engine Options

The 2024 NX offers the 2.4L turbocharged four-cylinder (NX 350), 2.5L hybrid (NX 350h), and 2.5L plug-in hybrid (NX 450h+). Cylinder 3 is the third from the front on all inline-4 configurations.

Typical Causes

  • Ignition Coil Problems: Turbo boost increases ignition demands
  • Spark Plug Wear: Turbo applications stress spark plugs
  • Boost System Integrity: Leaks cause lean misfires on NX 350
  • Fuel Injector Issues: Direct injection system concerns
  • Carbon Deposits: GDI engines accumulate valve carbon

Diagnostic Process

Identify your powertrain variant first. Use Lexus diagnostic equipment for comprehensive data access. Monitor boost and misfire data on turbo models. Test ignition components systematically.

Repair Recommendations

Replace faulty ignition coils with Denso OEM components. Install properly specified spark plugs. Repair boost system leaks on NX 350. Professional carbon cleaning addresses valve deposits.

Parts & Tools for This Case

Based on our investigation, these parts may be needed for this repair.

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