Misleading misfire codes
 

I recently purchased a 2006 Scion tC with a hundred thirty thousand miles on it the service engine light was on the guy claimed it was an O2 sensor or gas cap I changed the gas cap it's still reading that code is also giving me a Code for P0300, P0301, P0304 these are all misfires the car does not misfires as far as I can tell and being that I grew up in the garage my dad was a dirt track race car driver I would feel something like I thought. So I'm thinking that maybe I need to look into this being that I cannot get the service engine light to go out the previous owner was a first owner and said that the light goes on and off for a couple weeks and it has not gone off at all I do not feel any lack of power and I'm curious as to what may be causing this.

Also I read a lot of the forums here that's a spark plugs and coil packs and I'm not sure that that's the problem either being that I don't feel a misfire it is a 5-speed straight drive I love her so maybe someone can help me with figuring out what's going on thanks in advance