COBB Downpipe Stainless Steel 3" With Catalytic Converter Focus ST 2013-2018

99% of 100


  • 304-Stainless Steel
  • Includes Hardware
  • 200 Cell Count
  • 2-Bolt Flange

COBB 3" Stainless Steel Downpipe with a Catalytic Converter for all 2013, 2014, 2015, 2016, 2017 and 2018 Focus STs.

COBB's 3" Stainless Steel Downpipe is a direct replacement system for your 2013-2018 Focus ST. The downpipe features full 304 stainless steel construction, a 4" flex section and a high-flow catalytic converter. Installation of the catted downpipe produces big power gains without the excessive sound of an off-road downpipe.

COBB Downpipe Features:
- Full 3" 304-Stainless Steel Construction
- Durable 4" Flex Section
- Magnaflow 200 Cell Count Catalytic Converter
- CNC Machined V-Band Flange
- 2-Bolt Flange
- Includes 2-1/2" and 3" Gaskets
- Comes with All Necessary Hardware
- Installation Instructions

Full stainless steel construction means the COBB downpipe holds up to the elements extremely well with high quality metal. Beautiful TIG welds seal all seams perfectly, resulting in zero exhaust leaks. CNC mandrel bent tubing creates the perfect fit every time for a no-hassle installation. Tubing is 3" in diameter with a 4" flex section. The COBB downpipe features a 200 cell count Magnaflow catalytic converter. The high flowing cat decreases restriction for better exhaust flow while. The COBB downpipe bolts up to your factory turbo with a V-band flange as well as your factory or stock style aftermarket cat-back. Includes 2-1/2" and 3" gaskets to match stock or aftermarket cat-backs.

Tech Tip: The flange on this 3" downpipe will work with smaller diameter cat-back exhaust systems, such as 2-1/4" and 2-1/2". CJ Pony Parts has installed a variety of 3" downpipes onto smaller diameter cat-back systems without any issues.

The COBB 3" cat-back exhaust system is a perfect compliment for COBB's 3" catted downpipe. You can take full advantage of COBB power by upgrading to a full turbo-back exhaust system that includes the cat-back exhaust and downpipe. For the ultimate upgrade, you can then pair the full turbo-back exhaust with a COBB Accessport V3 for an amazing bump in power.

Order COBB's 3" Stainless Steel Downpipe with a Catalytic Converter for your 2013, 2014, 2015, 2016, 2017 or 2018 Focus ST from CJ Pony Parts today!

California Residents: Proposition 65 Warning

Note: This item is not CARB (California Air Resource Board) exempt and is not legal for sale or use in the state of California.

Installation Difficulty


Intermediate skill is required for this installation.

Installation Videos

Video Transcript

Ever since we started doing Focus ST videos here at CJ's, the number one requested video we receive is for a downpipe install. Downpipe is basically the gateway between your turbo and your cat-back and upgrading your downpipe is going to increase exhaust flow, make a turbo spool up faster and, best of all, it's going to make horsepower. Today we're going to remove our factory down pipe and replace with this high flow catted downpipe from Cobb.

Just like the other Cobb parts we've installed, their downpipe is a high quality piece. It's made of 304 stainless steel. Viewed as a high flow 200 cell catalytic converter. It's going to be a direct replacement for the factory downpipe on all 2013 and 2014 Focus ST's. Cobb gives you everything you need to install the downpipe on your Focus. They provide a link to download the instructions, include new hardware, even include two different gaskets: one 3 inch gasket for use with an after-market pipe back and then a 2 1/2 inch gasket if you're still using your factory cat back.

For this installation, you need a lift or a jack and jack stands, 3/8 ratchet, 12 inch extension, 15 mm socket, 13 mm socket, 10 mm socket, T30 torx bit, 14 mm wrench, 13 mm wrench, 7/8 wrench or oxygen sensor wrench, flashlight and safety glasses. You're going to start the installation under the hood of your Focus ST. You're up here because you need to disconnect the oxygen sensors before you can remove the factory downpipe. they're located pretty much straight back here in the back of the engine. To make life easier you can remove the cowl or you can remove your inlet to give you more room but if you're careful, you can remove the sound symposer tube and you can reach down and disconnect them.

You try to do the installation without removing the cowl or the tube which we're going to try to do. Start by pulling this tube off. Push that out of the way. This line here has a little clip. You pop the clip off. You move that out of the way as well and you come in from this side and get down and get to the oxygen sensor plugs. It's a little pushbutton tab and you carefully separate them. The plugs are different so don't worry about putting it back together. They go in together the same way.

Now we can move on to the car. The downpipe's located right here coming off the flange for our cat-back and going up to our turbo. To access the front part of the disconnected band clamp, we're going to start by taking off this cover. Once the cover's off we will start by removing this rear brace. It's held on by six pieces of hardware going across the back here. Next we'll remove the hardware that's going to connect our cat-back to the factory downpipe. Now we're going to remove the downpipe mount which is located right here. The downpipe's above it. The mount comes down. See now we actually removed when we installed the engine mount previously.

Now we'll start removing the V-band clamp that holds the factory downpipe to the turbo. Before we remove it we want to reach up here and follow the oxygen sensor wires. There's a couple clips we have to disconnect. Now we can start the battle to remove the factory downpipe. It's kind of tight up in here. It will come out. You're going to have to wrestle with it a little bit. Possibly pull this pipe down a little bit further by removing the rear bracket to get enough clearance, but it will eventually come out.

We're going to remove the hanger bracket to give us a little more room here. Here you can see the Cobb stainless steel downpipe versus our factory downpipe. You can obviously tell the curves are much better, it's much higher quality. Catalytic converter's much smaller but it's also much more efficient. It's going to allow more exhaust flow, allow the turbo to spool up faster and in turn make more power as well. From the factory piece here, you're going to use the clamp over again. You want to remove this ring gasket here as well as both oxygen sensors. Install all three onto our new Cobb pipe.

The locations of the oxygen sensors are specific so we want to make sure where you remove it you put it in the same spot in the new pipe. Also want to make sure you put a little bit of anti-seize on during the installation. You want to be real careful when you thread in the new sensors that you don't cross thread them. We'll get our clamp started then put it up into place. To make life a little bit easier we're also going to put the hanger on for the back of the pipe, install it here before we put it back on the car.

Our assembly's ready. We put it back on our Focus. We can start fishing it up into place. Again, be careful of the oxygen sensors. You might want to twist it a couple times to get everything to go where it needs to go. You find the new pipe goes in a lot easier than the old one came out. Let it rest there. Now reconnect the clamp. Now we're going to loosely connect the clamp that holds our downpipe to our turbo. You don't want to tighten it all the way up yet. Loosely put it in place. Then we'll get the mounts back on and then we can tighten it down.

Now we'll reinstall the hanger bracket. Now we use the hardware and the proper gaskets applied by Cobb to reinstall our cat-back to our new downpipe. The last part of installing the downpipe itself is to tighten the clamp of the turbo. Now we're going to reinstall the brace we removed earlier. You'll have a lot more space with the Cobb downpipe versus the factory one so you actually might be able to reach up and connect them from underneath. If you can, make sure you do push the wires away from the catalytic converter and tie them so nothing happens to them.

If you do manage to get both oxygen sensors connected from under the car, just don't forget to go up top again and reconnect your sound symposer too. We're actually able to get both of our sensor reconnected from underneath the car so our last step is to reinstall the splash pan. And your installation's finished. Now we have our pipe installed, we'll start it up. It is noticeably louder. I wouldn't say it's night and day but there's definitely a louder tone from the exhaust system. It's also going to run rich with the new pipe so you do want to make sure you get it tuned properly when adding a downpipe.

Now we'll do a couple sound clips for you. Again, this car has the Flowmaster cat-back and then obviously we just installed the Cobb downpipe. You want to make sure you do upload a new map to your computer for the downpipe before you do any kind of real heavy driving.

With the Cobb downpipe we can definitely hear our turbo more, we can definitely tell it spools up a lot faster. The exhaust also sounds better. Installation isn't too bad. Besides removing the pipe itself and disconnecting the oxygen sensors, really shouldn't be too tough for you to do at home on jack stands. Installation will take you around two hours. Should be back on the road in no time.

Vehicle Fitment

This product will fit the following Focus years:

Only registered users can ask/answer questions. Please sign in or create an account.
Write Your Own Review
Only registered users can write reviews. Please sign in or create an account.
Complete Your Package
Add to Cart