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Focus ST Cat-back exhaust

Your Focus ST

Pick your year to see what fits.

Every US Focus ST (2013–2018) is a hatchback with a 6-speed manual and the same 2.0L EcoBoost engine, so the same parts fit every year.

+3–8 whp (est.)
Medium$680–$7601.5–2 hrs
All Focus ST mods

Why do it

The stock exhaust is quiet and heavy. A 3" cat-back gives a deeper sound, a little more flow and less weight. No tune needed.

Tools you'll need

Parts to buy

Double-check fitment before buying.

Before you start

  • The factory exhaust is one piece over the rear axle, so you cut it to get it out. You'll need a reciprocating saw.
  • The MBRP kit comes with new clamps, a gasket and hardware, and uses the factory rubber hangers.
  • Spray the nuts at the downpipe with penetrating oil the night before.

Video guide

Focus ST MBRP XP 3" cat-back install
by CJ Pony Parts (with MBRP) on YouTube

The exact MBRP exhaust we list, installed with help from an MBRP engineer.

Watch the whole video

Steps

  1. Lift the car

    • Raise the car on four jack stands or a lift and let the exhaust cool completely.
    Watch this step (2:21–2:42)

  2. Remove the support bar

    • Remove the support bar under the car that crosses the exhaust.
    Watch this step (2:40–3:11)

  3. Cut the stock exhaust

    • Cut the pipe just behind the weld in front of the rear axle. That's the easiest place.
    • Wear safety glasses, and support the pipe so it doesn't drop on you.
    Watch this step (3:09–3:27)

  4. Remove the rear section

    • Pull the rear muffler off its three rubber hangers: one on each side and one up over the axle that's hard to see. A hanger tool or spray lube helps.
    Watch this step (3:27–3:48)

  5. Unbolt the front pipe

    • Remove the two nuts where the front pipe meets the downpipe, and lower the front section out.
    Watch this step (3:46–4:09)

  6. Feed in the over-axle pipe

    • Feed the over-axle pipe in from the back of the car toward the front.
    • It's a tight fit with the bigger 3" pipe. Take your time; you may need to gently bend the heat shield edges out of the way.
    Watch this step (4:09–4:46)

  7. Hang the tailpipe section

    • Slide the tailpipe section onto the factory hangers.
    • Leave everything hand-tight for now so you can line it all up later.
    Watch this step (4:44–5:22)

  8. Bolt on the front pipe

    • Fit the front extension pipe to the downpipe with the new gasket. It only fits one way, angled slightly toward the passenger side.
    • Hand-tight for now.
    Watch this step (5:22–5:55)

  9. Fit the front muffler and tighten

    • Fit the front muffler and the last connecting piece with the clamps from the kit.
    • Once everything lines up and nothing touches the body, tighten everything from front to back.
    Watch this step (5:52–6:47)

  10. Line up the tips

    • Center each tip in the bumper opening and set how far it sticks out. Tighten them one at a time, starting with the left so you can fit your tool in.
    • Refit the support bar.
    Watch this step (6:47–7:37)

  11. Check for leaks

    • Start the car and listen for ticking or puffing at the joints. Feel near the joints (not on them, they get hot) for air.
    • Check again after the first drive, once it has heated up.
    Watch this step (7:35–8:20)

How to know it worked

Did this guide work for you?

Safety first

  • Park on flat ground, set the parking brake and chock the wheels.
  • Never get under a car held up only by a jack. Use jack stands.
  • Let the engine and exhaust cool first.
  • Disconnect the battery before unplugging electrical parts.
  • Wear safety glasses.
  • If something doesn't match your car, stop and ask a shop.

Follow your part's instructions and your service manual's torque specs.