No, the oil trap isn't a replacement part, but if you ever take one off, you'll be tempted to clean it out when you see all the crap in there. That said, they are built out of some pretty crappy plastic, cost about $40 new, and take a few days for the dealer to order one (wife's car has been parked with the hood up because I don't have the time to work on it during the week.) You can decide whether or not its worth order a new one.

My advice: it's such a miserable job to do, i would buy all the parts you need ahead of time (and a knock sensor because the hard to reach one resides right next to the oil trap), replace it all at once and sleep soundly knowing that you won't have to think about it for another 10 years. Kenner suggested this in one of his posts, and I didn't believe him. Now look at me, I've bought all the same parts as he did, only I didn't have them sitting on the toolbench when I started the project.