SW20 O2 Sensor location

Okay, I may look like an idiot... But I can't find this oxygen sensor. I'm getting told I only have one sensor, other people are saying two, but I can't even find one!! 

Thanks in advance!!! 

There is a temp sensor further down past the cat (at least on the turbo). Could be mistaken for a second O2 sensor, but there's definitely only one.

the O2 sensor on the turbo is mounted on the dump pipe just after it leaves the turbo you will see the prong sticking out near the heatshield if looking from the top of the engine bay just near the firewall
 
http://www.google.com.au/imgres?um=1&hl=en&safe=active&sa=N&biw=1920&bih=882&tbm=isch&tbnid=LdZzCvXCy-Zh-M:&imgrefurl=http://www.mr2.com/forums/non-turbo-engine-talk-modifications-swaps/Toyota-MR2-41922-oxygen-sensor-location-help-pls.html&docid=R0o_zf1c5LRgbM&imgurl=http://www.lovehorsepower.com/images/TurboInstallation/dump_pipe_o2_sensor.jpg&w=1024&h=768&ei=mFCOUPD8MuWViAfk3IHoCA&zoom=1&iact=rc&dur=125&sig=114740007653537372652&page=1&tbnh=124&tbnw=170&start=0&ndsp=47&ved=1t:429,r:1,s:0,i:73&tx=120&ty=68
 
the second one most likely people are reffering to is the catalytic converter overheating probe located in the cat converter itself
its not the second O2 sensor as there isnt one.
 
cheers

Only one sensor, checkout purple's pic if you have a turbo.

heres another picture of it
http://www.mr2.com/forums/turbo-engine-talk-modifications-swaps/Toyota-MR2-81757-o2-sensor-pigtail-help.html
 
look to the bottom right where you will see the yellow coloued handle for the Oil dipstick - njow look to the right side and little bit above of that ( the thing with the black wire running to it) thats the O2 sensor.
 
to find this place in your car
open engine lid cover
then go stand near the drivers side rear wheel
then lean into the engine bay and look to the right side and this picture is what you will see
 
cheers