I bought an air/fuel autometer gauge a few months back and today began to install it. Im running the o2 sensor wire to my o2 sensor but my question is i have a obd1 and the o2 sensor has 4 wires i tapped it in to the white wire and the gauge at full throttle reads fine but at idle sweeps from rich to lean constantly. The 4 wires i saw was 2 black 1 white and one green... Anyone know exactly which wire to attach it to?

 

it's normal for it to sweep lean/rich when at idle

 

is the white wire you got it right and the gauge is reading right as long as it doesnt go lean when you on full throttle your good but if it does is hook up wrong or your car is running lean.

 

yup its suppose to jump from rich to lean...its just the meter scanning. so you should be fine.