Box(resonator?) before the catalytic converter?

So I'm getting ready to redo my exhaust on the 1998 5.4 expedition. Before both cats but after the headers there is a box, I'm assuming its a resonator. I have a 1992 ranger and it had the same thing before I took all of it off. Looking inside the "box" on the ranger it was just hollow, so I'm guessing its the same on the expedition? Whats the purpose of this thing? Damping noise, collect exhaust to be pushed through the cat? What happens when its removed and its just headers, cat, muffler? Improved performance or sound? Thinking about leaving it on and just true dual after the cats into a xpipe cherry bomb muffler back to dual. 

2 Answers

  • 2 months ago

    This is exactly what’s on mine, like I said it looks like a empty box, but I haven’t took it apart to see what’s inside. And where they connect at that Y pipe I plan on cutting that off and true dualing it out the back

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  • Anonymous
    2 months ago

    A picture of this "box" would help.  If you are installing a cat back exhaust, leave it alone.

    • Grant2 months agoReport

      I couldn’t post a pic in a reply so I submitted an answer to my own question with a pic of my system.

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