I'm currently using a "non-lethal" steel pipe, and yet ALL enemies that I hit with it drop dead. Just failed me a mission where the side objective was not to kill anyone.

all non lethal weapons can kill enemies.
when their health initially hits 0 they will fall down like any dead enemy but you may notice that they are writhing and sometimes moaning. sometimes though it seems you can only tell the difference by your reticle or cross-hair color.
if they are hit again with a non lethal weapon once in this state they will die though.

some cyberpychos will just freeze in place when attacked with a non lethal weapon and their health gets to zero but they can still be killed also.

if you are experiencing some sort of bug where all enemies just die no matter what, i would try different weapons and loading earlier saves to see if the issue persists.

Also note only the pipe does non-lethal damage. If you've got cyberware, mods or the like applying additional damage or status effects there's a good chance they won't be non-lethal. Similarly be careful where you target - even a non-lethal weapon can cause the head to explode on a critical hit, which unsurprisingly counts as a kill (the tranq missile is equally effective at dismemberment if you're not careful with aiming too). Body shots tend to be less risky, limbs too unless you've got perks increasing the dismemberment chance (although I'm not sure if that's still a kill; I've blown arms and legs off with the tranq missile but I didn't check it actually killed the target).

AFAIK the only weapons you'll never kill with outside of takedowns are fists (minus gorilla arms) and the System Reset quick hack.

I threw a PAX mod in a smart pistol (while using the proper implant to link the weapon) and it worked great for hunting down those cyberpsychos.

I was going to try the unique non-lethal melee weapon male V finds in the room you share with a certain Corpo, if you end up doing so, but I accidentaly scrapped it.

Scrapping a little too fast were ya? I feel your pain.

Perhaps there may be a BUG with the cyberpsycho missions regarding Non lethal. Most of my Cyber psycho missions I been using a critical damage mod on my Ajax and not the Pax non lethal mod and still was rewarded for not killing them. When I noticed I did not equip the Pax mod I did equip it in my slot, damaging out the critical hit mod. Been playing most of CP2077 with Pax mod equipped and passing the crime in progress missions. Ill go back to the fallen and put one to the head earning street cred I still have a few CP missions to complete. Enjoying the game so far.

Leg - Bat kills people
Leg - SirphallusStiff kills people
Punch people they die.
put people in a box they're counted as dead even though you choked them out

Guys it must be all our faults right guys comeon we did this, this is why we have Ants

it's buged - like everything else in this game

In this game, lethality is actually a bit more complex than in most other games. It's also not explained at all.

For example, you can take down enemies with lethal weapons without killing them: I once shot a Cyberpsycho in the legs with a lethal revolver, and it counted as non-lethal.

I also used a non-lethal gun to shoot someone in the head, and they died.

From what I've seen, lethal/non-lethal only increases the probability of taking down enemies lethally/non-lethally. The only guarantee for a non-lethal takedown is to use System Reset or choke them from stealth, and for a lethal one it's to attack them while unconscious or snap their neck from stealth.

Also, dumping bodies is lethal. It makes sense in some cases (like dumping them a freezer), but makes no sense in others (like leaving them in a wardrobe or garbage container).

It's also possible that shooting their arm off will kill them even if you take them down non-lethally afterwards (blood loss). At least, I've never seen someone survive after losing an arm. But that's probably because I never switched to non-lethal after blowing their arms off either...

My cyberware allows all hits to be non-lethal.
I have to hit them a second time, when they're down, to kill them, unless its a sniper critical with like 8K+ damages.

If i hit them when they're down, they die, but my street cred would go up.
I took out (incapacitated) all the 'psychosis people with sniper rifles and only killed the first one as i ... hit them again not knowing.

Try not to spam the left click. When their health drops to 0, they get knocked down. If you hit someone who is knocked down with a non-lethal weapon, they die.

As I have been playing very often and doing my best to observe carefully when using lethal and none lethal weapons I started to notice it depends on the hit box locations too. Even the mods I have equipped in my cyber deck too will let a fellow user know if its lethal or not. Even your equipment such as grenades. It will let you know if its lethal or not.
And of course when you are being more stealth and sneak up behind a NPC it will give you the option for a lethal or non lethal take down

If this was part of the design regarding weapon effects and impact on the NPC bodily damage, I actually like it. The CP2077 universe , most people have some or most bodily modifications and may help prevent them zeroing out so soon.

Perhaps the devs can improve on this if this I the case. Let's say if GIG, world quest and main mission objects are to bring them or keep them alive and the user went to far during combat, the objective has a bleed out timer with a reasonable time limit over the object to use a hypo on them before they zero out. Same goes for innocent by standard. Also depending what difficulty the user is playing the game on, using a hypo will subtract one from your inventory, don't have enough? You can craft some up. Or, I see that there are gorilla arm limbs and I just stumbled across a second set that will do fire damage. Have gorilla arms that do electric and if you have these equipped before going into combat, the user can walk up and use their hands like defibrillator paddles the way Watson does in Apex legends.

I am literally using a non lethal baton (with no mods on it) and trying so hard to not even hit people on their heads but yet they still die immediately. This is defiantly broken and not meant to be this way either. A weapon is non lethal or it is lethal yet all my non lethal weapons are easily killing people. I take all my lethal weapons out of my inventory to try a don't kill anyone mission and people still die and I fail it so quick. I have tried just using non lethal quick hacks instead of using my weapons and they still end up dying. This is so broke. Also I am on ps4 incase people aren't having the same problems.

Took me a while to figure that one out... I suppose hiding someone in a wardrobe in the blistering heat of a desert would do that.

I hope that's wrong.

Most of the people I hid were in those containers inside stores and warehouses.... I just assumed they'd wake up after I left and be fine.

After all, if you want to knock people out for stealth and non-kill purposes, you NEED to hide them.