My z is getting poor gas mileage and low horsepower. When scanned the computer reads po300 multmult misfire. Iv checked all the ignition coils im possitive its notna coilcor plug or anything ofothattnature, and iv looked for vacuum leaks its not a consistent issue either it will come and go. No big rattles or ticks

 

Welcome- there's lots of P0300 issues on the repair forum lately. Have you done a search and read much lately? Here's one from an easy search:

https://my350z.com/forum/maintenance...eshooting.html

 

How many miles does it have, and how are you positive it's not a coil pack or a plug..?

 

Heaven forbid he take it to nisan for a proper diagnosis

 

Can someone help me i dont know how to make a post for the life of me