[M_a_t_t]

I've wired up my arduino like this and go to download the code and it comes up with error messages. I know how to code a little but not something this extensive. I decided to use the older version because the schematic was simpler and the more up to date one didn't have any functions that I really needed. I was hoping someone who already knew how the code worked could fix it for me. I really just want the instant and tank mpg, miles left in tank would be nice but I don't really need it. Thanks for any help.
Matt