The 2022 Lexus GX delivers luxury off-road capability powered by the proven 4.6L V8 engine. When your GX displays a P0304 code indicating a cylinder 4 misfire, understanding this reliable powertrain helps guide effective diagnosis.
Understanding P0304 in the GX
The 4.6L V8 in your GX is part of Toyota's UR engine family known for durability. Cylinder 4 is located on the rear of the left bank of the V8. The engine control module monitors combustion events through crankshaft position analysis with precision.
V8 Engine Considerations
The 4.6L V8 has an excellent reliability record across Toyota and Lexus applications. When misfires occur, they typically indicate specific component issues rather than systemic problems. The V8 uses individual coil-on-plug ignition allowing targeted diagnosis.
Diagnostic Approach
Access the cylinder 4 ignition coil on the left bank. The GX's engine bay provides reasonable access despite the large engine. Inspect spark plug condition—Toyota's iridium plugs have long service life. Check for vacuum leaks in the intake system.
Resolution Process
Replace spark plugs with Lexus/Toyota specifications if worn. Test ignition coil output. The quality of Toyota/Lexus components means thorough diagnosis should precede parts replacement.