2005 Acura Mdx O2 Sensor

Hi guys… not sure if this is the correct forum but I am wondering if anyone can help me out. I have my engine light and vtm4 on. The night before I ran into a big puddle and the light came off. Now I have the code P0135 which is O2 Sensor heater circuit bank 1 sensor 1. Can you guys tell me which location I can find this or any diagram on how to fix this. And also what triggers the vtm4 for the light to come off? Thanks for the help.