'96 3.4 EVAP sensor part mismatch?

CEL came on, ran diagnostic at auto parts shop and got P0450. Store clerk ran the specs and came up with replacement part Dorman 911-610. They wanted $140 for it, found it new online for $40. Part number seems to match but when I went to install I found what looks like the right place to switch it out alongside charcoal canister and it looks *almost* right with electrical harness, mount, and 2 out of 3 tubes lining up but the new part has a large cylinder/cap where the third tube should attach. The part number is printed on this piece and I'm wondering if this is a functional part of the part or just a removable piece (it looks like it could just pop off). I tried to firmly but gently remove it but didn't want to force it. Any tips for how to proceed?

(I'm a carpenter and as truck is not made of wood it is alien territory for me, so please forgive my newbie ignorance. Thanks for any help!)

 

Heh heh, I got it to pop off. Well, color me embarrassed. Anyway, I'll leave this here in case anyone else runs into this issue.