Is vinegar an enzyme cleaner?
No. Vinegar contains no enzymes at all.
Vinegar is dilute acetic acid, usually around 5%. It cleans by lowering pH, which dissolves alkaline deposits and kills some bacteria. An enzyme cleaner works by an entirely different mechanism, using proteins that cut organic molecules into smaller pieces. The two things are not variants of each other.
Why People Think It Is
Because it sometimes appears to work. Fresh urine is acidic, then turns alkaline as it breaks down, and that alkaline stage is where much of the sharp ammonia smell comes from. Vinegar neutralises some of it on contact, so the smell drops noticeably within a minute and the job feels done. A few days later it is back.
What Vinegar Does Clean Well
Quite a lot, and it costs almost nothing. It dissolves limescale in kettles, showerheads and dishwashers. It cuts soap scum. It strips mineral buildup off glass. For hard water problems it outperforms anything enzymatic, because those deposits are not organic and enzymes have nothing to act on. Keep it. Use it for that.
Where It Fails, And Why
Cat urine contains uric acid, which forms crystals as it dries. Those crystals are not soluble in water and not neutralised by acid. They sit in carpet fibres and in the pad underneath, and when humidity rises they release the smell again. This is the whole reason a spot you cleaned in spring smells in August. Vinegar does not touch them. Enzymes do.
Do Not Use Both At Once
Acid denatures enzymes, which is a polite way of saying it destroys them. Applying vinegar and then an enzyme cleaner to the same spot without rinsing thoroughly in between will weaken or kill the enzymes before they start. Pick one. For urine, pick the enzyme cleaner.