Your SLS only has one converter, and I believe that's why it issues a bank 1 designation. Bank one is the bank of cylinders that includes cylinder #1, which on your vehicle is the rear bank. A catalyst efficiency code with no other symptoms, is corrected with catalyst replacement. I am not certain of the assignment of oxygen sensors for sure, but I believe you have a Bank 1 Sensor 1, a Bank 2 Sensor 1, and a Bank 1 Sensor 2. It is the pre-cat sensors(B1s1/B2s1) versus the post- cat sensor(B1s2) that determine whether or not the catalyst is functioning.
Tuesday, September 14th, 2010 AT 11:52 PM