Need a lambda sensor for my 52 plate bug wrx it's the front upstream one, trouble is I'm being told by motex and other parts places there's a few different options"????? How do I know which one to buy '!!!! Has anyone for the part number? Total minefield

 

i THINK what you needs is a 4 wire zirconia sensor... if you are ok with a soldering iron then you can buy a universal one for roughly £18

Just bought one for mine and am fitting this weekend, fingers crossed it works.