Cylinder 4 Misfire Detected

What is P0304?

P0304 indicates a misfire specifically in cylinder 4, meaning that cylinder is not firing properly or at all. This is a critical powertrain issue that can cause severe engine damage if driven for long, and it's commonly triggered by ignition, fuel, or compression problems. Based on real owner data, this code is frequently reported in vehicles like the Chevrolet Spark, Honda Accord, and Chevrolet Tahoe.

Common Causes

• ●Faulty spark plugs or ignition coils (commonly mentioned in owner discussions for maintenance)
• ●Head gasket failure (specifically cited in Honda Accord cases causing multiple misfires)
• ●Fuel delivery issues like clogged injectors (implied as a common misfire cause)

Symptoms You May Notice

• ●Engine runs rough or shakes noticeably (owners describe rough running and vibrations)
• ●Check Engine Light flashes or is illuminated (implied by diagnostic trouble code triggering)
• ●Loss of power or engine going into 'limp mode' (reported in Honda Accord cases)

How to Fix It

• ●Replace spark plugs and ignition coils ($70-$400, moderate difficulty based on owner mentions)
• ●Repair or replace head gasket ($1500-$4300, high difficulty and cost based on Accord reports)
• ●Clean or replace fuel injectors ($200-$600, moderate difficulty)