2005 Chevrolet Cobalt P0300 Code: Fuel System Diagnosis and No Air Leak Detected
The vehicle is a 2005 Chevrolet Cobalt with a persistent P0300 random misfire code. Fuel quality has been verified as good, and no air leaks have been detected during inspection. The fuel pump operates normally with adequate pressure. No visible signs of fuel system issues or vacuum leaks are present.
Replaced spark plugs and confirmed fuel pump function; fuel pressure is within normal range, and no air leaks were detected during inspection.