From what I can see from the picture,it looks like the solenoids for the smog system.On a Mustang,these are called the TAD(thermactor air diverter valve)and the TAB(thermactor air bypass valve)but I'm not sure what they're called on a Acura.If a vacuum hose connects to one of them,it might be the EGR vacuum solenoid.If these are thermactor valves,the hoses should connect to pipes leading to the heads and catalytic converters.I could be totally wrong though,but this is my best guess.They might also have a somewhat different name but do the same job.They should be for the smog system though regardless of their name,if they're what I think they are.Good luck

Filter box for cooling

Cold air filter box.

If you don't know what it is, how do you know it's bad?

Have you thought to take it a parts store and ask clerk to look at it? Maybe they will know what it is.

It's on my 1993 Acura Legend. It has three prongs/heads and they connect to 3 or 4 tubes. I need to replace it, but I don't know what it's called.