P0300 MISFIRE PROBLEMS

[Rawbee]

2014 Chevy Sonic RS

Guys. Please help.
I just bought a brand new Ignition coil set from Autozone. Slapped it in and when coming to a stop or at a stop for a minute or two i start to get a shaky idle. Not superbad. Just enough to still worry me. I also replaced all plugs with brand new ac delcos iridiums.
What else could be wrong?!? Please help!!!

 

[pwyskowski]

I had the same problem recently with my 2012 Sonic LS.
The mechanic I hired did what you did and didn't have any luck so he flushed the fuel injectors and that seemed to help. He said cheap gas can have crud in it that builds up inside.