How to replace the catalytic converter on a Citroen C1 (Peugeot 107 or Toyota Aygo)

In this video, you will learn how to replace the catalytic converter on a Citroen C1 (the procedure is the same for the Peugeot 107 or Toyota Aygo). Open the bonnet and disconnect the battery, starting with the negative terminal. Then lift the front of the car and place it on two axle stands; you will need to remove the front bumper.

There are three screws above the bumper that you will need to undo with a 10 mm socket; at the level of the wing, there is a screw on each side that you will also need to remove. Finally, remove the five screws that hold the lower part of the bumper.

Now that the bumper is free, gently pull it towards you, but first, push in the plastic clips that still hold the bumper. The catalytic converter is a vertical cylinder next to the radiator.

First, disconnect the lambda sensor on the top by pulling it out, then unscrew the sensor with a 22 mm socket. From under the vehicle, unscrew the two clamps of the exhaust valve with a 13 mm socket; separate the two elements using a crowbar.

Use a socket to remove the screws that secure the element, and then unscrew the support. Now the catalytic converter is free, and you can remove it from the front at the level of the radiator.

Remember to remove the worn gasket, while the heat shields can be reused by remounting them on the new one. Clean the seat where you will remount the gasket and install it, fit the sealing gasket on the catalytic converter, and install it in place by first screwing in the upper screws and then the support screw.

Refit the two spring screws of the clamp from underneath.

Now refit the lambda sensor and reconnect it. You can remount the bumper, starting with the clips and then inserting the screws. Lower the car. Reconnect the battery.

On some vehicles, it will be necessary to inform the ECU that the catalytic converter has been changed.