How to Replace a Toyota Rav 4 Catalytic Converterby Jody L. Campbell
Toyota Rav4s have two catalytic converters. The front one is bolted directly to the manifold in the front of the exhaust system and the second one bolts directly to that. In most cases, the converter that fails will be the rear converter. Converters fail after a while clogging, breaking down internally (which is a result of clogging and overheating), and have inlet or outlet pipes that crack or leak exhaust. Having to replace them requires experience.
How to Replace a Toyota Rav 4 Front Catalytic Converter
Put the Toyota Rav4 on a car lift and bring all the way up. Put all the listed tools into the tool cart and wheel it near you where it's out of the way but where you can access the tools easily. To remove the five nuts going to the manifold, set up the ratchet with a long extension, the swivel, and a socket. In some cases if the nuts are deteriorated, you may need to switch the socket for a nut extractor.
Put on the safety glasses and light the torch with the striker. Heat up the nuts with the torch, being careful not to heat the studs up as well. It's a tight area and you'll have to know how to handle a torch and adjust the level of flame to be small enough to do the job but hot enough succeed. When the nut is cherry red in color, turn off the torch and remove it with the ratchet, extension, swivel, and socket or nut extractor. Carry on this procedure for the other four nuts.
Light the torch and cut the two or three bolts (some of the rear converters have a three-bolt inlet and some have two of the Rav4s) out of the rear flange. Cut them from the front converter side so you do not incur any damage to the rear converter. When the bolts are cut with the torch flush to the flange, turn off the torch, put on the safety gloves, and knock the rest of the bolt from the flange with a punch and hammer. Be ready to get out of the way or catch the front converter as it will drop out as soon as it's free.
Allow the system to cool down. Install the top of the front converter with a new gasket to the manifold by threading on some new nuts by hand. Tighten them one at a time with the pneumatic gun, extension (either small or long), swivel, and socket until they're tight.
Insert the gasket to the rear of the front converter flange connection and attach with the hardware (bolts, nuts, washers). Tighten with the gun, the small extension (if needed), swivel, and hold the head of the nuts in place with a hand wrench. Remove the cart and tools and any debris on the floor, lower the Rav4, and start it up to check for any possible exhaust leaks.
How to Replace a Toyota Rav 4 Rear Catalytic Converter
With the Rav4 raised on a lift, locate the oxygen sensor bolted to the rear converter. Follow the wire to the plug and separate it by unplugging it. You may need the screwdriver to press in the clip lock. As with the front converter, load the tools into the cart and have nearby.
Put on the safety glasses and light the torch with the striker. Cut the bolts from the front flange connection with the torch. Cut them from the rear converter side of the flange to avoid damage to the front converter flange. When the bolts are cut flush to the flange, turn off the torch and knock them out with a punch and hammer. Repeat this step for the rear converter to rear exhaust pipe flange. Be careful when the last bolt gets punched through. The converter will want to drop, but you'll notice it's still affixed to a rubber exhaust hanger. Remove the hook of the converter from the hanger.
Remove the bolts from the oxygen sensor studs. They may be deteriorated and you may need the extractor nuts to help you. Don't worry about the nuts or studs and damaging them. You're going to replace the nuts and the studs are part of the converter. There will be new studs on the new converter. All you need is the oxygen sensor.
Insert the oxygen sensor into the new converter. Replace gasket (equipped with new converter) and nuts and tighten with the ratchet, extension, and a socket.
Place the hook on the new converter through the rubber hanger and attach the front flange to the front converter with gasket and hardware (bolts, washers, nuts). Attach the rear flange of the converter to the rear exhaust pipe flange with the gasket and hardware. Tighten the bolts and nuts with the gun, swivel, socket, and a hand wrench. Plug the oxygen sensor back into the plug. Remove the cart, tools, and any debris, lower the Rav4 and start the engine to check for any possible exhaust leaks.