Chevrolet Avalanche 1500 misfire on cylinders 3 and 4 on Chevrolet Avalanche 1500

Some Chevrolet Avalanche 1500 owners report experiencing misfires in cylinders 3 and 4, often attributed to faulty or fouled spark plugs that may require inspection and replacement. Additionally, issues with ignition components such as wires and coil packs can persist even after changing the coil pack, indicating the need for further investigation of the ignition system. Diagnostic codes P0303 and P0304 specifically point to misfires in these cylinders, aiding in identifying the problem. Owners should also consider other components like fuel injectors and overall engine health, as these can impact the misfire issue as well. Repair costs can vary based on the underlying cause, with common solutions including replacing spark plugs, ignition coils, or cleaning fuel injectors. If problems continue despite basic checks, seeking professional assistance from a mechanic or dealership equipped with diagnostic tools is advisable for a thorough analysis.