Where to buy O2 sensors
 

Any suggestions on a good place to buy. I need 4 for a 97 Boxster $564 total at Pelican.

Rock Auto -- got one earlier this year for < 100

I buy all my parts at partsgeek.com

All of them are less than $91. Some as low as $60.

Why do you need all 4? Normally it is the 2 front ones that fail. And are you sure that it is the O2 sensors and not something else causing a problem? All too often, it is an air leak or something like that if you are getting codes on both sides of the engine.