If that O2 Sensor has no voltage thats your problem. MAP is probably picking up high temps because you are running lean. It could be a seperate problem but you need to get the lean codes to drop first. If the O2 Sensor has correct voltage replace the MAF. MAF is 250+ O2 is about 150 and you will get at least 1 hour labor to fix either (however they take about 15 mins).