I get asked quite a lot where to get Oxygen/O2/Lambda sensors.
I had an issue on a car I 'looked'
at yesterday with a dead O2 Sensor, so thought I would post info up.
Here's a link to a good source :
http://www.lambdasensor.com/main/subaru3.htm
These come with the OE style connector at a fraction of the cost (£60 approx.) of genuine items (£150+).
If ordering select 'Direct Fit' and not 'Universal'.