Engine bay - oxygen sensor seal
 

I am hoping someone can direct me to where I might find the rubber seal that the drivers side post cat oxygen sensor wire goes through. It is round and about the size of a silver dollar.
I was changing out the oxygen sensor and the dam thing fell somewhere behind the catalytic converter. Very frustrating.
Maybe a dealer item? Thanks in advance.

According to 964 PET illustration 202-00 it comes with a free oxygen sensor...

Yes, it is part of an OEM O2 sensor wiring. Do not think they are sold separately.

Thanks guys. I'll look it up.

I could not find any information on this seal/ grommet. Local auto parts had some generic round grommets that took a little moification and all is now good. My main issue was to protect the sensors wires from rubbing against where it passes through the body into the engine compartment.