Hello, I think I can help, possibly even sell you one.
A very quick look round seems to show that the Freelander K series CAT is the same as other Rover K series installs notably the Elise and MGF which have DeCat pipes available. A diagram of a Freelander pipe is here
http://www.brookwell.co.uk/products/freelander-parts/freelander-exhaust and this looks just like the one I had on my Elise I just looked at.
I have an Elise CAT sat on my bench so can email over a scan of the flange and main dimensions if you want to to check or if you cant find any other sites to back up the link above.
No the Elise CAT I have is infact a hollowed out one that "blew" at a sprint event and had its guts knocked out with a screwdriver just after practice (I finished 200ths of the blinking class record for Castle Combe after sepnding most of the day under the car). You can have that for £10 plus postage as it is basically now a decat pipe with the added advantage of looking like a cat under quick inspection.
If you want a new decat pipe then look at
http://www.eliseparts.com/categories.php?category=39 make sure you get a S1 pipe as the S2 is different.
I assume he knows that the car is highly likely to fail on emissions whit the cat removed so he may end up having to keep his cat and put it on for MOT, plus I think running no cat is illegal on vehicles made after a certain date (not sure). Why do it I was thinking its not worth it for power unless its a rally car, however I believe there are concerns about CATs cracking when hot if used for wading and, general knocks if used off road in earnest, and possibly if overlanding removing a cat may be 1 less thing to go wrong.
If he takes the old cat offf and its working make sure he stores it inside somewhere dry (like a loft) not a garage. I think mine being stored in a dampsih barn while I used a decat pipe for racing may have been why the original one failed (soggy guts).
PM me as im off about and about an may not check the forum.
