my2003 2.2 did not have one, i took the pipe off (after much effort) to find that there wasnt one!!! i was a bit pissed off!
to save yourself a bit of time, when you come to have a look, undo the bolts holding the pre-cat to the manifold and stick yer fingers in there! if it feels empty then u dont have one! i should have done this but silly me i just undid all of the bolts on the join to the manifold, undid the pipe from the middle section, removed the sensors, and then decided to have a feel duh!