Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
The code P0300 is a misfire code. Need to figure out which cylinder is causing the misfires.
Common problems are spark plugs or coils.
Do you have a code reader or is it a scan tool? Need to determine which cylinder is causing the misfires. One of the cylinders will have more misfires.
When you changed the spark plugs. Did you notice a line on the outside of the spark plugs?
Vacuum leaks or poor fuel can cause misfires also.