Hello all. This is my first post. I recently purchased a 1998 Subaru Legacy Gt. I recently replaced the head gaskets, timing components, etc.. Anyways.. The car fires up and runs, however, it idles a little low and the motor has some hesitation. I recently read the code and it was for bank 1 sensor 2. When I took sensor out I went ahead and bench tested it and it was producing voltage just fine.I also checked the wiring harness and it was fine. Now my question is, what would cause the downstream 02 sensor to trigger a check engine light. Is there an exhaust leak between the two cat converters?