Replacing the catalytic converter on a 2001 Honda Odyssey will save money and can be done without special tools. The retaining nuts on the converter may be seized from temperatures they endure over time, so plan to spray them for several days with a good penetrating oil to help loosen them. A replacement converter for the Honda model is available from Honda dealers or larger auto parts stores.
Raise the front of the Odyssey with a jack and position a set of jack stands under the front suspension. Lower the jack, setting the van on the jack stands. Be sure the van is stable before sliding under it just behind the front tires.
Locate the catalytic converter in the exhaust system; it should be just behind the head pipe. Look for the heat shields that wrap around the top and bottom of the converter and the two mounting bolts that hold the shields in place on either side. Remove the bolts with a socket and ratchet and remove the heat shields from the converter.
Locate the three mounting studs on each end of the converter and remove the nuts from the studs with a wrench. Afterward, pull the rear pipe assembly back from the converter until it clears the studs. This allows you to push the pipe off to the side and out of the way.
Pull the converter back from the head pipe until the studs clear the mounting flange. Then lower the converter to the ground. Two brass gaskets are used to seal the converter to the flanges; make sure they come out as well.
Position a new converter under the van and raise it into position. Align the studs with the front flange and slide them together loosely. Then slide the rear pipe onto the studs at the back of the converter.
Tighten the retaining nuts onto all the studs a few turns just to hold the converter in place. Insert a new brass gasket into gap between the catalytic converter and the flange on each end. Torque all six retaining nuts to 25 pound-feet with a torque wrench and socket.
Install the heat shields around the new converter, install the retaining bolts and tighten them with a socket and ratchet. Raise the front of the van off the jack stands with a jack and remove the jack stands. Lower the van onto the tires and remove the jack from under it.
