[jcslocum]

If the cat is fried then the 02 sensor will still be working to correct the A/F ratio. It should not just sit still. You can find 02 sensors less expensive. They are literally all the same with a different plug on the end...

$62 at Rock Auto

http://www.partsgeek.com/gbproducts/SC/96050-08004161.html?utm_content=SC&utm_term=2010-2011+Porsche+911+Oxygen+Sensor+Bosch+9A1+606+124+0 0+Left+10-11+Porsche+Oxygen+Sensor&fp=pp&gbm=a&utm_source=google&utm_medium=ff&utm_campaign=PartsGeek+Google+Base&gclid=Cj0KCQjwlf_MBRDUARIsAD8Gj8BiagKDcj9H1zO8C_Dp E6njJlbl1koxO090jnzHf59PlgtS0WpBGp4aAn9FEALw_wcB&ad=47433965052