no there arent any mods to my fuel system, the only mods i have on my car, is a intake n a catback exhaust...if the odb-2 to odb-1 conversion ur talkin bout is bout my tranny , well i udes a ENJO hydro to cable conversion kit, and just swapped all the items from my stock tranny to the b16 tranny... i think there were 2 sensors n this thing that went in the back by where the axles go in, i think but not sure this part was for the tach....