Coolant Temp Sensor location?

[Yeti]

Originally Posted by IllusionX

The check engine is probably throwing a misfire code on one of the cylinder.

I'm repeating myself, Have you check the coil packs?? You are a mechanics, you should be able to diagnose which cylinder is malfunctioning.

try this for the PC ODBII reader.
http://obddiagnostics.com/ProgWin.html

Just checked with my mate there - he changed the plugs, but not the coil packs - trying to borrow another Yaris to swap the coil packs over - I'll bring the OBD cable in tommorrow and try that software you gave me the link to, thanks.