Correction on code 12
With a no start, code 12 make sense as no ignition voltage to the car computer. Go figure.
I had a Infinity 1990 V8 and I believe code 12 was normal, nothing wrong , all moniting sensor working.
Today I got a chiltons manual from the library, so I coud get some info on my emission sensors, and the test for them. There is where I found a whole bunch of info on codes. They puplish the codes in chapter 6..
I got the V6 3vz engine. 5s is the four cylinder engine.
Sorry for jumping the gun on this one,