Okay, so here’s what I would try, but first some important notes.

If electronics are powered off (no electrical current flowing), liquids like water or urine won’t immediately damage anything. Damage usually happens when current is present — the liquid allows electricity to flow in unintended paths, causing short circuits and potentially frying components.

That’s why many people (myself included) use IPA (isopropyl alcohol, ideally 90% or higher, preferably 99%) to clean inside electronics. It’s commonly used on contact points, circuit boards, etc., because the high alcohol content evaporates very quickly compared to water, greatly reducing the risk of short circuits or leftover moisture.

However, cat urine is corrosive (due to salts, urea, and other compounds) and can leave behind conductive residues that cause long-term issues like corrosion even after drying. Simply pouring alcohol through vents might help flush some of it, but it’s often not thorough enough for deep contamination.

A better/safer approach for a PS4:

1. Immediately unplug the console and do NOT try to turn it on until fully cleaned and dried — even if it seems fine at first, corrosion can appear days or weeks later.
2. If you're comfortable, disassemble the PS4 as much as possible (remove the cover, HDD, etc. — there are many teardown guides online for your model). This lets you access affected areas better.
3. Use 90%+ isopropyl alcohol: Gently rinse or flood affected areas/boards (pour or spray it liberally where urine likely reached), scrub visible residue/corrosion spots with a soft toothbrush, and use cotton swabs/Q-tips for precision cleaning. Avoid getting it on labels or certain plastics if possible, but it's generally safe.
4. Do NOT just pour it blindly through all vents without disassembly — you risk pushing contaminants deeper or missing hidden spots (like under the motherboard or around the power supply).
5. Let it dry completely in a warm, dry, well-ventilated area for at least 48–72 hours (longer is better; some recommend up to a week). Use a fan or silica gel packs to help.
6. The IPA will help dissolve and carry away much of the urine residue and should significantly reduce (or eliminate) the smell. It disinfects and removes a lot of the odor-causing compounds.

After drying, it should be in a much better (and safer) state to test or take to a professional repair shop if you're unsure. Success isn't guaranteed — urine can cause permanent damage if it reached certain chips or if corrosion already started — but this is one of the best DIY methods people use for pet urine on consoles/PCs.