How to Replace Exhaust Manifold 2003-08 Toyota Matrix

Okay, friends, you're going to need to get underneath the hood and we're going to go right to the negative battery terminal. Go ahead and remove that and set it aside so there's no way it can make contact. The next thing I like to do is take off the cover. Because I'm going to be leaning over the engine, I don't want to push on the plastic and potentially break it. So now looking at the backside of the engine, you can see where the manifold is. You can also see the O2 sensor. Go ahead and follow that wire up and we're going to disconnect it.

Now it's going to be time to remove the O2 sensor. Go ahead and use an O2 sensor socket and remove it. All right. There it is, friends. Always check your threads to make sure they're in good condition. I always check the connectors and you also want to make sure that you remember that this is your upstream O2 sensor. Set it aside. Now we need to go ahead and unbolt the shield away from the manifold. Next, we want to make our way underneath the vehicle. And what we want to do is find that downstream O2 sensor and then follow the exhaust pipe right up to this area right here.

On both sides of the pipe, you're going to find this and it's called a spring bolt. It's going to be spring-loaded so it's going to be under a little bit of tension, but we're going to use our 12-millimeter and we're going to go ahead and remove both of them. There we are. Do the same to the other side. Next, located directly over your right front axle underneath the manifold you're going to find a bracket. You need to go ahead and remove that bolt as well. All right. The next thing you need to do is go ahead and remove your manifold mounting nuts. You're going to find there's five of them. There's three in the center that you can see and then one on each opposing side.

Go ahead and remove all five, and then we'll start removing the studs. Okay. Obviously, our stud came out as well. If this happens, you just want to go ahead and separate the two for reinstallation. At this point, this is going to be the last stud/nut that's holding the manifold on. I'm going to hold the manifold so it can not fall. We'll get this right out of here. Now, we'll grab the manifold and come right up through the top-up here. There it is, friends. Now, the next thing we need to do is go ahead and sand down the port of the engine where the manifold is going to go onto.

So, get yourself a nice flat standing block, that's very important that it's flat and some sandpaper and we're going to get back there and we're going to sand it so it's nice and clean. So let's just take our sanding block along the backside here. And we're just going to go ahead and sand this down and what we're paying attention to is along where the ports are, you just want to make sure you get all that carbon buildup off of there. And, of course, make sure there's no crud that's going to be in the way. You want a nice smooth surface.

Okay. Now that we have that cleaned up as best as we can with the sandpaper, it looks really good. The next thing I want to do is go ahead and spray down inside those ports with a little bit of compressed air to make sure we can get out any of the debris. Do them all. Okay, friends, now it's going to be time to get your mounting nuts off of the studs that hold your manifold to the engine. To do that, there's a couple of different ways that I'd like to tell you. You can either grab on with some locking pliers right along this ridge right here on the smooth area. Just kind of grab right on there, hold it tight, and then try to get this off using your 12-millimeter.

Or what you could also try to do is maybe if you have a vise, like what I do right here, take a couple of pieces of wood, put them right in between there, take this, slide it in between the two pieces of wood. Once you have it in between, go ahead and snug this up so it's nice and tight. The wood's going to grip right onto that stud and it's not going to damage it. If you were to do it otherwise without the wood, more than likely the vise teeth would kind of damage the threads on there and you'd have to replace the threads.

Let's go ahead and use this. See if we can remove it. For a third thing that I'll show you just in case neither of those worked for you. If you were to take an inverted Torx bit right up here, a socket that looks just like that. That'll grip onto the stud. You can also take a wrench to hold onto that 12-millimeter. We'll go ahead and take that inverted Torx. And now we should be able to break the stud free from the nut and remove it. There we are. I've got that almost all the way off of there. At this point, I'll just grab onto it with some locking pliers, if you have access to them, and I'll finish taking that off. There we are.

Once you get all your nuts off of the studs, you want to go ahead and clean up those threads so they're nice like these. This looks great. So we'll continue. Now the next thing we're going to do is start in all these studs and then we'll just go ahead and bottom them out. So now that they're all started, let's go ahead and bottom them all out. We're just gonna go until they bottom out and go a teeny bit more, and that's it. You don't want to strip out the head. Do the same to all.

Now, on the lower side of the manifold pipe, what we want to do is actually put on our brand new gasket here. To do that, you would just kind of put it over the end of the pipe, and then we're going to tap it on with a nice wooden block and a hammer. The next thing we're going to do is put on our nice new gasket here. Should just line up with those studs. Perfect. Now we're going to take off our mounting bolts for the shield on the front of the manifold. There we are. The lower shield off as well.

Okay. So, the next thing we need to do is get the manifold in here. A couple of things you want to pay attention to is the manifold poles have to go over all your studs. And then also the lower aspect of your manifold has to go into that pipe down there. Let's go ahead and get our manifold right in here. It's coming down. Put it right over those manifolds studs. Slide it in. There we are. Let's grab our nuts. We'll stud them all on. There's one. We'll stud them all on before we snug any of them up.

All right, let's snug them up now. Now we're going to go ahead and torque these to 27 foot-pounds. Do the same to all. All right. Let's get our nice new shield back on here. Start in on all your bolts once again before you tighten any of them up. Okay. All of them were started, let's go ahead and snug these bolts up. There we go. Do the same to all. Now, we're going to put back in our O2 sensor. ...a little hole there. We'll start it in, bottom it out, and then we'll snug it up.

All right. So, that's bottomed out and it's nice and snug. Let's go ahead and reconnect it in now. Take this. It comes right up here. Click it in, give it a nice tug. Make sure it's not touching up against anything it shouldn't be. This looks great. All right. Let's get our lower shield on here. Now that we have them all started, let's go ahead and snug them up. Just go ahead and bottom it, give it a teeny bit more. Do the same to all. The next thing we need to do is set up our spring bolts to attach our lower pipe to our manifold.

So, just put them both together like this. Okay. Just slides right over, and then go ahead and stud it in. We're going to start both of them and then we'll snug them up. Now we're just going to go ahead and snug these up. So, it just bottomed out. A teeny bit more. Do the same to the other side. Next thing we're going to do is put on our bracket that goes from the manifold to the engine. Let's go ahead and stud in all of our bolts, and then we'll snug them right up. Now, let's go ahead and get our cover back on here.

Now, let's reconnect our negative battery terminal. Make sure you tighten that right up. We have everything back together. Let's go ahead and start the vehicle and make sure we don't have any exhaust leaks.