How to Replace the Catalytic Converter on a Trailblazerby Christian Killian
Replacing the catalytic converter on the Chevy Trailblazer is a great job to tackle at home. The converter bolts in place between the front exhaust pipe and the muffler, making it easy to get to and change. The converter is a little heavy, so be careful when you remove the bolts to make sure that it does not fall on you. Replacement converters are available through your Chevy dealer, as well as from most major auto-parts stores.
Raise the front of your Trailblazer with a jack and support it on a set of jack stands positioned under the frame rails. Slide under the passenger's side of the vehicle and locate the catalytic converter in the exhaust pipe between the engine and the muffler.
Locate the oxygen sensor in the converter. Follow the wire from the sensor to the wire harness connector and disconnect it from the harness. Place an oxygen-sensor socket on the sensor and remove it from the converter with a ratchet. Set it aside.
Loosen the two bolts on the mounting flange between the rear of the catalytic converter and the exhaust pipe using a socket and ratchet. Remove the bolts from the flange and pull the pipe aaway from the converter. Push the pipe aside.
Move to the front of the converter and remove the two mounting bolts between the flange and the front pipe with a wrench. Pull the converter out and remove it from under the truck.
Position a new converter in place under the truck. Lift the converter up into place and install the retaining bolts from the front pipe to the front flange on the converter. Leave them loose for now.
Position the rear pipe up against the rear flange and install the rear mounting bolts loosely. Tighten the front bolts by torquing them to 33 ft.-lbs., then tighten the rear bolts to 33 ft.-lbs. as well.
Install the oxygen sensor from the old converter into the new converter and tighten it with a oxygen sensor socket and ratchet. Connect the wiring harness connector from the oxygen sensor to the wiring harness connector on the truck. Push the connectors together until they lock in place.
Raise the front of the truck off the jack stands with a jack. Remove the stands from under the truck, lower the jack and remove it from under the truck.