I own a 406 GTX Hdi. Its been great up until about a few weeks ago when the exhaust sounded like it had a very very slight blow to it. It never really got any worse so I have left it as is until it really needs doing. Yesterday when I left work I noticed a distinct lack of power. Very flat response from the engine and the exhaust sounded a tiny bit more 'blowy'.
Today took wifey to the shops and the power loss was even more evident. Exhaust sounds much the same (slight blow) but when I change gear at around 4000 revs there is more of a puff of the old diesel smoke than usual. As of twenty mins ago the power is awful and the engine management light has come on.
A few years ago I had a VW corrado and the symptoms were similar when my CAT broke up inside. Spoke to a friend and he said it may be turbo pipe split or the catalyst.
Any ideas?
I phoned main dealer but the costs have scared my innards out in large volumes!! ( I think you get my drift ).
Love the car but will have to do the work myself as funds are very tight.
Been looking on the net for ages and finally found this site. Nice to see some fellow 406 lovers.

Cheers
Andy
TCO