06 cobalt aftermarket gauges

hope im in the right spot... but anyway im putting in an air fuel guage says i have to tap into the o2 sensor which wire would that be ther are 4 wires on it 2 white a gray and a black

also doing a oil pressure gauge. were could i tap in for that.. thanks

What company's a/f gauge are you putting in? it should give you an idea in the booklet of which one to try. Honestly without a wire diagram you cant be for sure but id try the grey one, it seems more likely.