RTH: O2 sensor gaskets; which side down? (1 Viewer)

[surfj40]

Swear I searched for this and could not find a thread that got right to the answer.

Replacing the O2 sensors with OEM - need to know which side of the gasket goes down on exhaust, which side up to the sensor.

Original ones (I assume) were toast and essentially fused to the exhaust and could not be used as a guide.

Thanks

 

[surfj40]

or.......does it really matter which side of the gasket is up or down?

Do I need to worry about this?

I just want to make sure I get and keep a good seal.