hi, i need a sensor for my exhaust...

basically i just got a new front downpipe cat, for my 306, i was gonna use the old lambda, but can i frig get the old one out..

so just been looking for one the same part number as is in the old pipe..

do i need the exact same one, or do you just buy for a car model cos ive seen one listed for my car but the end 3 number are not the same...

the one in my old pipe is number
0258 003 668, but what ive seen listed i think for my car
0258 003 717

thanks