Engine shaking when gas kicks on

I've had the Prius for 4 yrs, got it w 49k. Has 223k. When engine kicks on now at idke I experience a rough shake at times and it feels like its sputtering. It happens randomly and sometimes it doesn't happen at all and it's not as bad at a higher speed but sometimes still happens. Previously a code was tripped stating misfire, or vacuum leak so I was think it may need new spark plugs but im reading about coils failing as well? The engine code has since disappeared and the shaking is random. If someone has had experience w this and can point me in the right direction its appreciates. Thanks!

 

I have not. Im not the most knowledgeable with vehicles. I spoke w a hybrid tech and they said it may be a blown head gasket? I don't see oil mixed w coolant tho. Going to see if I see any white smoke at tail. Going to have the spark plugs and coils replaced. I bought a 4 pack online that seems identical to these and they said with a little luck that may fix it. Otherwise, probably the gasket. Since you mentioned EGR I'll look into that now.