The sealing rings are synthetic resin with chamfered ends. Check the condition of the sealing rings, and replace them only if they are worn, distorted, or damaged.
For a better fit, squeeze sealing rings together slightly before installing them.

Apply ATF to the new sealing rings, then install them on the secondary shaft.

After installing the sealing rings, verify the following:
The rings are fully seated in the groove.
The rings are not twisted.
The chamfered ends of the rings are properly joined.
Control Locations
* : If equipped ...
Fuel and Emissions System Description - Catalytic Converter System
Catalytic Converter System
Warm Up Three Way Catalytic Converter (WU-TWC) and
Under-floor Three Way Catalytic Converter (Under-floor TWC)
The WU-TWC and the under-flo ...
Drive Belt Auto-Tensioner Inspection
Turn the ignition switch to ON (II), and make sure to turn the A/C switch
OFF, then turn the ignition switch to LOCK (0).
Check the position of the auto-tensioner indicator (A). S ...