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!!! 

NA - On the B-pipe just before going over the rear subframe.
 
Turbo - Right at the top of the elbow coming off the hot side of the turbo. :)

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.

You are probably referring to the secondary O2 sensor mounted after the cat on CA-Registered USDM models. (Because they have anally retentive emissions regs to adhere to)

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

You've confused me :(

Are you saying that there is no o2 sensor? Because that can't be right... 

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

Josh.69

You've confused me :(

Are you saying that there is no o2 sensor? Because that can't be right... 

seriously, did you even look at the pic i posted????
theres only ONE O2 sensor on the turbo MR2 and its shown in the picture i posted, ive also told you roughly where its located on the car in my previous post

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
 

The link doesn't work on my computer mate relax, don't have to be so rude. But I've found it now, cheers.