Realistic Oxygen Meter V1.1.1

Ever feel like the Oxygen meter was just a glorified stamina bar? Other space games make you keep track of your suit’s oxygen when you’re in vacuum. This mod overhauls the oxygen meter to work like a suit O2 meter. This is similar to other space games, and like the Subnautica series, but it is balanced for the speed of Starfield’s gameplay.

The mod does several things to accomplish the goal of transforming your oxygen meter into a proper oxygen meter. These changes are largely only active when you’re in a vacuum or when you’re in a thin atmosphere. When you’re in a pressurized area, or when you’re in atmosphere, the game will mostly treat your O2 meter as it did in vanilla, except running will cause it to drain slower.

When you are in a vacuum, you will slowly lose oxygen as your breath from your suit’s stores. When you run out of oxygen, your suit’s CO2 meter will fill, and when it is full you will rapidly lose health and die of asphyxiation. (You cannot die in atmosphere.)
Running, jumping, carrying too much in your inventory, and power attacking will all drain your O2 meter quicker than regular activity.
Thin atmospheres have enough O2 to keep your suit’s stores from draining, but you will also not regain oxygen in thin atmospheres. You can still lose O2 from strenuous activity in thin atmosphere. (The Personal Atmosphere power creates a thin atmosphere.)
Holding your breath to steady your aim no longer drains O2 from your suit, but it does cause CO2 to build up in your blood.

Not all hope is lost in the black of space though, because you will be able to stock up on O2 Tanks to keep with you to give you more time exploring before you need to come back and fill up your O2 tanks again!

O2 Tanks and Large O2 Tanks can be crafted at a Pharmaceutical Lab.
If you install the optional file for Oxygen Tanks in the Wild, the oxygen tanks you normally find around the map in certain areas will be replaced with the usable O2 tanks from the mod.
O2 Tanks can be found on enemies and in first aid containers as loot.
O2 Tanks can also be purchased from certain vendors.
Oxygen Refill panels are scattered around the world which can refill your O2 meter without using up a tank.
With the Tanks in the Wild optional file, Emergency Oxygen Masks can also be found in the world which pause passive O2 loss for 2 minutes.

Everything to do with Oxygen is rebalanced for the mod. Legendaries and armor mods which give bonus oxygen will give a lot more of it, since you’re not going to be gaining it back all of the time. Perks have been slightly altered so they play fair with the new oxygen mechanics as well. If you feel like any of the balance of the mod needs to be tweaked, be sure to leave a comment!

Installation:

Unzip the archive and put TNProperOxygen.esm and (If using the optional file) TN_Oxygen_Tanks_Wild.esm into your Starfield/Data folder (most likely under Documents/My Games/Starfield/Data), or let your mod manager install the file.
Ensure that archive invalidation is enabled in your StarfieldCustom.ini. (Look below if you don’t)
Install Baka Achievement Enabler and SFSE if you don’t want achievements disabled.

If you haven’t already done it for another mod, this is what needs to go in your StarfieldCustom.ini:
[Archive]
bInvalidateOlderFiles=1
sResourceDataDirsFinal=

Credits:

TheOGTennessee