ok i got the gauges install know for the wires. i know popsitive negitive thats easy. i need to know where the other wire (the purple one) for air/fuel ratio. i know the o2 sensor. isn't that the piece right after the intake? well theres a plug on that.(don't know how to take it off. i'm i on the right track? well if i get in there what wire (color) do i splice into? seems to be a stupid question and i have a book on my car it just tell more about a stanza and nothing ever really about my car. thanks guys this helps alot.

240sx 1991 2.4 liter hatchback.

 

ok for your air fuel, you'll wanna attach the wire (purple)if its an autometer to the wire coming from your 02 sensor which is located on the exhaust manifold of the car. it should be on the driverside of the car on the manifold near the firewall. you will see a sensor sticking out of your exhaust and that will be the one. as far as which wire there im not sure which one it is. typically it is always the white one, but im not sure if our cars have a white wire because i havent really looked that close at it. but i hope this helps a little. if you have any other questions feel free to ask.