P0300 CHEVROLET -

Question

Changed the spark plugs in my 6.0 liter Blazer SS as well as plug wires. After completion started engine and am getting a slight rough idle and engine light has come on. This engine has always idled very smooth prior to this. I cannot figure which cylinder might be miss firing. When disconnecting one coil feed at a time I cannot notice a difference in idle roughness. Error code is p0300.

Answer 1

You should try checking for intake leaks. An air leak can sometimes multiple cylinder to misfire.