which wire is the O2 wire that comes out of the ecu? its a 99 gs. the reason i want to know is because im hooking up my air fuel gauge. i've searched everywhere.

 

Primary o2 sensor wire: Orange/Black - the #6 wire on the 32 pin connector.

 

thanks, is the gauge suppost to constantly move?

 

it usually bounces constantly. it'll go full rich when at WOT or when you're on the gas near WOT... it'll go full lean when you're up in R's and at closed throttle. its not a crazy accurate guage, but it looks neat and it helps.