How do you replace the catalytic converter on a 2001 Toyota Echo?

Answer 1

It's really not too hard, which is good since the dealer wanted $1400 just for the parts alone last time I checked. You have several options:

1) Cut out the old cat with a grinder or sawzall and weld in a new one, this option is the most work, but cost could be as low as $45. To do this right, you should remove the cat assembly from the car, cut out the cat, loosely attach the new cat, reinstall the whole assembly, spot weld the new cat, remove the entire assembly again, finish the weld, reinstall the assembly.

2) Take it to a mechanic that specializes in this type of work and have them do #1 for you. Cost could be around $300 to $500.

3) This is the option I would recommend - buy a new assembly that is a direct fit with new cat. Remove the old assembly and bolt in the new one, its a pretty easy job that takes about an hour (longer if you are doing it for the first time or if anything gives you trouble). Cost of a replacement assembly with new cat can be as low as $245 (cheapest place to buy online is partsgeek,

Part Number: 8042-05017868). Make sure you buy the mounting kit as well

Part Number: 8042-05120662 for $11 this comes with a gasket that is essential and you might as well change out the other parts from the kit considering it is so inexpensive. You will not need the nuts that come with the kit though.

To remove the assembly, you should start by removing the two O2 sensors. The O2 sensors can be removed with a pipe wrench or a special O2 sensor socket (available free to borrow from most big chain parts stores). For the front 02 sensor, you could just unplug it and take it out later after you have the entire assembly off the car or remove it from the assembly now to avoid possibly damaging it. Either way, you will have to remove the back O2 sensor from the assembly now. If your O2 sensors have more than 80k miles on them, now might be a good time to replace them.

Next remove the 2 bolts at the engine exhaust header, you will need a socket extension for this (if you don't have one, you can get a set of 3 for $8 from harbor freight, Item #39193) and probably a breaker bar to get it started (I slip a hollow metal pipe over the end of my socket wrench to give me more leverage). I highly recommend spraying lubricant on those bolt threads before you begin (deep creep is my favorite). Access the bolts from under the car, just a bit back from where the front O2 sensor plugs into its socket, follow the pipe from the cat and you will find the two bolts holding it on. Use the new bolts (from mounting kit) to figure out what size socket to use. After those are out, remove the mounting bracket from where the cat assembly attaches to the muffler assembly (toward the back rear passenger side tire). If that bolt is badly rusted, you may have to cut it out with a grinder and replace. There is a gasket in this joint as well that should be replaced, it is inexpensive. You may need to bang this joint a bit with a rubber mallet to get the two parts separated after you remove the bracket holding it together.

After both ends are detached, you will notice the assembly is still being held up on the car by some rubber blocks with holes in them. You have to slip the metal retainer bars from the cat assembly out of those rubber blocks, this is tricky the first time you do it, but not a big deal once you get the idea. I always shoot a little lubricant into the rubber channel and over the end of the metal part that has to be pulled though. I then use a small screwdriver (or awl), shove it into the rubber tunnel and pull the metal bracket through. There are four of these in total.

Once you have the assembly completely removed from the car, you can repeat the above in reverse. HOWEVER, remove and replace the exhaust header gasket FIRST, and make sure it is carefully pushed all the way down the pipe it goes over before you try to hang the new cat assembly. This is a very tight fit, be careful not to damage the new gasket (you can always get another one from local parts store for about $5).

Hang the new assembly on the rubber hangers. Then install the new bolts at the exhaust header. You will have to tighten these down very far to prevent all exhaust leakage from this joint. Try to tighten them evenly, doing a little on one bolt then a little on the other, etc. until done.

Clean the muffler joint completely removing all remnants of the old gasket, and add the new gasket. Reattach the muffler joint. This can be difficult if your replacement part does not exactly match the OEM part which has a small groove in it (look closely at the original part end and your new part end). You may need to do a small amount of sanding or grinding and a lot of hammering with a rubber mallet to get the new cat assembly into the the muffler assembly. Once in, add the bracket over the joint.

Realistically, the first time you do this, it could take 3-5 hours. If you were experienced and nothing went wrong, it could be done in half an hour.