p0304
Moderate
Toyota · SUVs
Cylinder 4 Misfire Detected
Quick Answer
Error code P0304 on your Toyota SUVs means: Cylinder 4 Misfire Detected. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
4Runner TRD Pro 2024Grand Highlander Limited 2024Highlander XLE 2024Highlander Hybrid Bronze Edition 2023Land Cruiser 1958 Edition 2024RAV4 XLE Premium 2024RAV4 Hybrid SE 2024Sequoia Capstone 20244Runner Limited 20244Runner SR5 20244Runner TRD Off-Road 2024Grand Highlander Platinum 2024Grand Highlander XLE 2024Highlander LE 2024Highlander Limited 2024Highlander Platinum 2024RAV4 Adventure 2024RAV4 LE 2024RAV4 TRD Off-Road 2024RAV4 XLE 2024Sequoia Limited 2024Sequoia Platinum 2024Sequoia SR5 2024Sequoia TRD Pro 2024Venza Limited 2024
Likely Causes
How to Fix It
1
Remove and inspect the spark plug on cylinder 4 for wear or deposits
2
Swap the ignition coil from cylinder 4 with another cylinder and clear codes to test
3
Test the fuel injector on cylinder 4 by measuring resistance and listening for click
4
Check for vacuum leaks near the cylinder 4 intake runner
5
Perform a compression and leak-down test on cylinder 4 if other causes are ruled out
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Spark plug
Ignition coil
Fuel injector
Intake manifold gasket
Related Error Codes