Which O2 sensor is Bank1 Sensor 1?

I've got the famous code of P0133 "O2 Sensor Circuit Slow Response (Bank

1, Sensor 1)" out of a 1998 900 4cyl... So is that the one in front of the engine?

When people the other one is "post-CAT" it looks to me like it is coming out of the CAT to me.... maybe there is another CAT up-stream?

Is there any drawback to getting a universal and doing the splice? Looks like $65 on thesaabsite.com vs. $160 something for the real Bosch that's available around

Thanks! meld