cel is on i have a slew of codes

hi guys.
i bought a 01 tacoma acouple months back. it didnt run when i bought it. we found i had a broken flex plate. we replaced with a used one and she runs good. ive been tinkering with it for a while now. i put it on the road today, and of course the cel light came on. it was on when i bought it but having the battery unhooked it went off. i had been running it around the yard and it stayed off.

so here comes the typical question why is it on? lol.
i have three codes
p0125
p0141
p1135.

these codes are off a mac scanner, these are in the order they apper.
i have been researching on here and am more confused then when i started.

my buddy with the scanner checked the coolant temp. in park with his foot on the gas, about 1500 rpm's it read at a high reading of 194 degrees. so i believe the t-stat is working fine. at a idle it read 180.

when i got done with my buddy and his mac scanner i had advance auto double check it. thy matched his codes in the same order.

there suggestion was to start with the cooloant temp switch. so theres no confusion cause i could be getting it wrong. its not the switch for the gauge but the one for the ecm.

so my real question is, if this was your truck where would you start? in some of the old posts i went through , i could tell there where some people on here that really new there shit. hoping one of you guys will chime in.

thanks again
and before i forget she is an 01 taco 4x4 4cl 2.7l auto.
any help is appreciated
thanks
doug