When your 2024 Lexus RX displays the P0303 code, the powertrain control module has identified consistent misfires in cylinder 3. The completely redesigned fifth-generation RX introduces new powertrains requiring updated diagnostic approaches.
2024 RX Powertrain Options
The 2024 RX offers the 2.4L turbocharged four-cylinder (RX 350), 2.5L hybrid (RX 350h/450h+), and 2.4L turbo hybrid (RX 500h). On the 2.4L turbo inline-4, cylinder 3 is third from the front. The hybrid powertrains have different configurations.
Common Causes
- Ignition Coil Failure: Turbo engines stress ignition components
- Spark Plug Issues: Turbocharged applications have specific requirements
- Boost System Leaks: Turbo models sensitive to intake leaks
- Fuel Injector Problems: Direct injection deposits or failures
- Carbon Buildup: GDI technology leads to valve deposits
Diagnostic Process
Identify your powertrain type first. Use Lexus/Toyota diagnostic equipment for detailed data access. Monitor boost pressure on turbo models. Test ignition components systematically. Check for TSBs addressing the new platform.
Repair Recommendations
Replace failed ignition coils with Denso OEM components. Install Lexus-specified spark plugs for turbo applications. Repair boost system leaks on RX 350 and 500h models. Address carbon buildup through professional cleaning.