Sluggish ... little exaust output

[RandallNeighbour]

Hugh, why didn't you get Hans to do all this? It would have been much less and he would have never let your car out of there with that diagnosis.

Cats don't go bad overnight like that. Sounds like you may just need a MAF or you have a fouled O2 sensor... a bad mass air fuel sensor can make the car run like crap. Ask them to put it on a PST tool and diagnosis it eletronically... which should be no problem for a good shop.

Now I had the same problem when one of the hoses coming from the fuel pump going into the sending unit. It just wasn't fully seated and starved the engine. Once it was back on it ran just fine.

You might have a failing fuel pump or one of those hoses. If the electronic diagnostics come out fine (ie, your cats are functioning well), have them check the fuel supply before they start selling you new cats (Porsche ain't gonna give you new ones in my opinion).

Instead of giving this shop a bunch MORE cash, call Hans and tell him what's going on and he may have some good advice for you.