my 4.6 runs like crap! HELP!

OK i have a 99 Ford Crown vic! Been runing fine since i'v had the car but about a week ago it started runing bad! Now i do all kinds of work to all kinds of cars but i just can't pin pont whats makeing it do what its doing! I scaned it and i got the codes of p1000, p0505, p0136, p0156, p1131, p1151! now i know what the codes are but witch ones doing it i'm going crazy trying to figure it out!
P0136 Downstream Heated Oxygen Sensor circuit fault - Bank No. 1
P0156 Downstream Heated Oxygen Sensor circuit fault - Bank No. 2
P1131 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1.
P1151 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 2..........Now i'm thinking whatever turns the heat on for the Oxygen sensor is bad but where its at i have no clue! So can anyone help me with this? Am i on the right track or am i just wasting time?

Have you checked the wiring ? Ford is really bad about wiring connectors losing connection.