Sounds as though you have bought the cold start heater plug. It warms the throttle housing when cold from starting.
quote "it just has a round brass part that sits in the throttle body"
The potentionometer sits on the end of the opposite side of the the throttle butterfly. Imagine a rod straight through from the throttle cable side, through thr throttle housing and out the other side. Where this comes out is where your potentionometr should fit (as a rule of thumb).
I'm not being paid by these guys and I have put them on the site before, but I found them really on the ball.
www.autoteknik.co.uk
Over night delivery and I saved nearly £100 by getting the genuine part but not in the Citroen bag. If you have a part number then even better but a fax picky or over phone description will work.
Xantia potientiometer, or is it????
Moderator: RichardW