COBB Cat-Back Exhaust System Stainless Steel 3" Focus ST 2013-2018

One of the first modifications many EcoBoost owners make is an aftermarket exhaust system. The factory exhaust leaves a lot to be desired. Adding an aftermarket exhaust is going to free up some weight usually, also free up some horsepower, and give you a much better sound.

In the case of the 2015 Focus ST, and don't expect the others to be any different, is the factory exhaust just has no character whatsoever. It's quiet and it's definitely not a performance exhaust fitting of the Focus ST. Thankfully, all the 2013 through 2014 exhausts are going to fit the 2015, so today we're going to upgrade our 2015's exhaust system using this Cat-Back from COBB.

This COBB Cat-Back is almost too beautiful to install on the car. It's made of 304 3 inch stainless steel, featuring CNC mandrel bends and beautiful tig welds on all of the pieces. It has 2 copper proprietary mufflers, and a set of 4 inch double wall stainless steel tips. Everything needed for installation is included by COBB.

While Ford did make some upgrades and changes to the 2015 Focus ST, the exhaust unfortunately wasn't one of them. It has the same bland sound as the 2013 through 2014. (engine revs) Nothing about that exhaust tone screams performance, but thankfully that's an easy fix. Let's get started with our COBB install.

With the exception of using 3 hangers instead of 4, the exhaust on the 2015 ST is exactly the same as the 2013-2014. That means the first step in removing the factory exhaust is going to be to cut it. What we're going to do is cut, you see right where this curve is, right behind the weld, so you can remove the two pieces separately.

We're going to remove the rear muffler now from the stock hangers. Carefully fish it over the axle. Here's a close up shot of the difference with the 2015. As you can see, the actual stud is there, but there is no hanger from the factory where this middle pipe would go. We do suggest if you are buying an after market system for your 2015 Focus ST, pick up a set of COBB's polyurethane exhaust hangers at the same time. That will give you a 4 piece set, which are much better than the factory hangers. It gives you everything you need to properly install the system. You can install it with 3 hangers, but it's more likely the system is going to move around and can create problems.

With the pipe cut and the rear muffler moved, now we're going to move up front and disconnect the Cat-Back from our factory down pipe by removing the two nuts on the other side of the pipe right here. The rest of the exhaust is still held in place by a hanger, so now you can remove this brace here. That will allow us to get the rest of the system off.

It's kind of hard to get the hanger removal tool in here, so a small pry bar will help you get this one off.

With the system off, we're now going to remove all of the factory hangers, so that we can replace them with our COBB polyurethane hangers. Spray a little lubricant on the stud and slide on the new hangers. The front-most hanger is a little different than the others. To install this one, I'm just going to push the hanger straight up and twist it into place.

Now we can begin the installation of the actual Cat-Back by installing two of the supplied bolts through our down pipe, and then choose the correct supplied gasket from COBB. If you have a stock down pipe you want the 2 1/2 inch gasket. If you have an aftermarket, COBB, or any other 3 inch pipe, you use the 3 inch gasket.

We're going to put the mid pipe into place by putting it on to the rear hanger. Install the retaining nuts on the front. We'll just get them hand tight for now. With that in place, we are going to reinstall the brace. It just give a little more support so the exhaust doesn't fall.

The next part's probably the trickiest part, and that is getting the pipe over the axle. It is difficult to get it to line up and get it into the insulator. It can be done, just take your time and get it over there. The part with the weld here is the back, so this is the part that goes over. I know it's a lot easier to take the hanger off and put it on the pipe first to get the rear one on.

We're ready to connect the front pipe to over the axle pipe. Install hardware and a gasket. We'll get that hand tight as well and move on to the tip.

Start by putting it into the hanger on the passenger side. Get an idea of where it's going to go and then grab the hardware. Now we'll go back through and tighten everything down.

Now let's fire it up with our COBB exhaust. The COBB's a nice step up over the stock exhaust. It has a much deeper tone. It's not loud, it's not buzzy, it's not raspy. It just has a nice tone to it.

The COBB exhaust would be a really good choice for somebody who wants a performance exhaust, wants the 3 inch flow, wants the added horse power, but doesn't necessarily want a really loud system. I'm driving the car, you can hear it. It's got a deeper tone than the factory. It's got a nice tone to it, it's just not overly loud. There we are, about 3,000 RPM, then we'll get up to highway speeds. Right now we're around 2,000 where most mufflers are going to have a drone to it. Really almost no drone at all. You can barely hear it. If you put it under a load, you get a little bit of a sound out of it, but overall you barely even notice it.

If I had to say, sound wise it's probable kind of similar to the MBRP sound, just not as much. The MBRP had a nice deep tone, but it was on the louder side. This has the same kind of deep tone to it, just not overly loud.

This system is going to be perfect when paired up with COBB's down pipe, because the down pipe always adds a little more volume to the system. In the couple installs we've done by added a down pipe, it actually got almost too loud. I think in the case of this, it’s going to give it a perfect tone. I love the sound of it, it's just not a very loud system. I want to call it more of an adult sound, but it's not that pricey, high pitched, turbo sound a lot of the systems make. This has a nice, clean, deep tone to it.

A wide open throttle doesn't change pitch either. It doesn't get raspy. It doesn't get tinny at all. It just keeps the same tone throughout the RPM band.