p1155 code on 2003 rav 4

I have a 2003 toyota rav 4 and have replace 3 sensors. The 2 lower downstreams and upper left side upstream and I still get the code p1155 bank 1 sensor 2. any ideas how to fix the problem I used bosch for the upstream and densco for the downstreams. could it be the brand bosch that is not working.