I normally get about 26-28 MPG on average. My check engine Light came on and I realized I was only getting 13 MPG. I had the code reads from the car and the mechanic stated I had a misfire on 2 + 4. I changed the plugs and gave the car a Fuel Treatment which cleaned out alot of black stuff. However I'm still having the same problem and now think I need to change the coil packs. Should I change the individual coils or the whole pack?
Anyone?