02 Sensors on 2001 Porsche Boxster S

I was told by the dealership that my 2000 Boxster S needs new 02 sensors. Do you reccomend changing all 4? Do you need to use the original parts or is there an okay replacement part? Will the check engine light go off after they are placed?

Asked by for the 2001 Porsche Boxster S
Depending on the mileage and how hard they are to get to would determine if I were going to replace all 4. High mileage/hard to access, replace all 4.
I would only use Porsche parts, or possibly a equivalent Bosch replacement part. Never use a generic, "one fits all" oxygen sensor.
As far as the check engine light, it depends on the codes that are stored that will determine if the light stays off. Do you know which codes were stored?