My wifes fiesta lamda sensor 1.4 zetec 03

[robj70]

Hi everyone . my wifes engine light has come on and I'm lucky enough to have a friend who works in fords so he plugged it in to his laptop and diagnosed the lambda sensor as being the problem . i've seen many prices for different sensors and I don't want to keep on to my mate , so can someone tell me if I have a Zirconia or titania sensor . how do i find out how long the sensor i need is ? are the universal sensors any good ? I know its the front sensor and I have no problem having a go at changing it myself . it's a 1.4 zetec on a 03 plate .