I have a 90 honda civic si my ecu is reading code 13 the atmospheric pressure sensor is defective.The problem is I can not seem to locate and do not even know what one looks like.I have tried with no success to find a picture or even any info about.I know where my map sensor is and that is not the problem the ecu code for map is 5-6.

Try looking here:
Atmospheric Pressure Sensor: In Passenger Compartment At RH Kick Panel
If I misled you before, I misunderstood
*(edit)* the two sensors discussed share some name title, leading to confusion
The colors were correct: Yel/Wht, Grn/Wht, Red/Wht