ECU question

the problem i am having on my 2008 dbl cab is that my check engine light keeps coming on and the codes that pop up are p0101, 136, 138,158,171,156. but the thing is i will reset them and then a little bit later the engine light will come back on and some of these will be there but then there are codes that pop up that are not Toyota codes. one of my friends said that possibly my ecu is fried and i know a while back i had a bad wiring job on my 02 sensor and he said that that could have caused the problem. im trying to figure out whether i should just get a used ecu and maybe that fixes it, because my mechanic checked all the sensors and everything else that he could think of and i recently just put in all brand new sensors so i know it is not bad sensors. Any help would be very appreciated.