I have a 300zx, i've heard that you can buy a code reader which is called consult or conzult, and all you have to do is get the software for free and you can download from some website, but where can i get the custom diagnostic connectors

The ConZult is a software application that was originally developed for the late model 300ZX (Z32)
It is basically a PC-version of the (very expensive) Nissan consult and offers
the same functionality plus extra features that are not possible with a Nissan consult.

Some of the Conzult's functions are:
- Checking and erasing DTC error-codes
- Manual operation of solenoids and relays
- Realtime monitoring of every sensor in the car
- Recording, analyzing and replaying sensor and solenoid data
- Access to the ECU's Read Only Memory (ROM), Fuelmaps, Timingmaps,etc.
- Temporarily adjustment of fuel and timing maps, ideal for tuning purposes

Most of all, the ConZult is an indispensable tool,
which can help in problem determination and is very useful for ECU tuning purposes.

so where can you download this free software, here is the link:
http://www.300zx-twinturbo.com/conzult/