So, came back to this game after a hiatus, and I'm trying to do the cyberpsycho missions nonlethally, but it seems like that's not an option anymore. I'm using nonlethal quickhacks, gorilla arms, and the nonlethal optics mod, and they still die. Am I missing something, or is there no way to just knock them out if you actually fight them (i.e., not stealth takedown or System Shutdown quickhack)?

EDIT: Aaaaaaand of course, as soon as I go back into the game and try it again, I manage to take one down without him just randomly springing a leak.

Yeah, the first one I tried, had him twitching on the ground, then *pop* sprung a leak.

In my personal experience it's most effective to use the analysis mod that makes all your weapons nonlethal, or equip a specific weapon with PAX, or use a stun baton or similar melee weapon.

I use smart guns with the analysis optiware. I find it usually works best to check my fire once the target's health drops low enough to make sure i'm not firing extra bullets that will still home in on the target after they've been disabled, and kick them over to death. I fire in bursts.

Alternatively, I Find it useful to use nonlethal quickhacks like overheat and shock. Most cyberpyschos i've seen are immune to system reset, annoyingly, but I guess that's because the devs want you to fight them like a minibosses instead of snap your fingers and turn them 'off' easily.

So far I've been 100% successful, other then one case where the cyberpsycho set off an explosion and killed themselves entirely on their own. I had to reload on that one.

If you're using Quickhacks, it should be easy.

Doing the same myself right now. Memory Wipe, plus Sonic Shock and Reboot Optics for good measure. Then just walk behind them, grab them and do a non-lethal takedown. Easy as pie.
This doesn't work on the mechanical Cyberpsychos though, so you'll still have to take those 2 down the hard way.

Can also use Contagion, but that takes much longer. Haven't tried System Reset, which causes the target to lose consciousness, on Cyberpsychos. Doubt it is that easy though.

Another option is using the Cottonmouth unique baton, with poison damage, found at Fingers' (ripperdoc) backroom on JigJig-street. Gorilla Arms, Hammer or baseball bats WILL kill them if your damage stats are too high.

Third and more risky option is using a firearm with burn or posin effect effect. Both status effects is considered non-lethal.

Doubt this works as well, but using the Projectile Launch System (instead of Gorilla Arms), with the Tranquilizer Rounds, could be worth a shot (...get it? "A shot"? Okay, I'll see myself out now).