I tried remapping my series but the head came off my two pound hammer so I have given up.

Positives are that the turbo spools faster and the engine breaths easier.

I dont know what the droneing is when you dropped your cat, that was one of the first things I did, had it for 4 months or so before fitting a straight thru. Didnt notice any change, even on the mway with just the decat, the straight thru made all noise!

I swapped the back section last night just to see the difference. However, it is not as responsive, think due to back pressure (or lack of). What I do like is the whistling of the turbo, very nice. But as above, when flooring it, it's a bit too loud for me.

I was only asking as I have a full stainless setup for a puma (mine is a td5). The only bit I can get to fit without cutting/sleeving/welding, is the back section. But that means it goes straight through. My backbox is also rusting so thought it would be a good idea to change it.

I'll just get a decent stainless steel back box with silencer as the noise I already had was a nice puurrrfect note and hopefully sell this twisted exhaust on.