First, we have to know what diagnostic code you are getting so we can isolate the problem. Please download a copy of the FSM (Factory Service Manual). It will help you a lot working with your car.
To extract the diagnostic code, here is the link to Maxima/I30/I35 FAQ. You can get a lot of useful info from that site.
zerothread/219453.
I was in Jeddah, KSA from 1986 to 1991, working with SAUDIA Avionics Training Department. Lots of luxurious and fast cars in that area.