My power steering pump is dead/dying. I attached my laptop to read codes off the ECU and check to make sure there was nothing else wrong. The only code I kept on getting was a code 55. When I would have my chipped 300zx ECU hooked up to my J30 the program would read a code 34 (or something like that) and it said it could not read the speed sensor (not worried about cause it can read the speed with the stock ECU, just as an example). Right now I am running the stock ECU and it is only giving me the code 55, which is labeled as "no malfunction" on the diagnostic program. Otherwise the diagnostic program picks up that the power steering pump sensor comes on when it is at idle, but since my power steering is gone/going it is stiffer than usual. Gonna replace the power steering pump and hope it is the only problem I have.