Well, the garage told me that while they were replacing the CC, the mechanic broke the front 02 sensor. They replaced it, checked for vacuum leaks, reset trim tables, etc. (at their expense of course) and the car is back to its old, peppy self.

When I asked why they replaced the CC they said that they drove it and it sounded like it was bad and then they found a hole in it. I asked to see it but they said it had already been shipped off to someone for reclamation of the precious metals inside.

To be fair, I looked at my receipt from 6 months ago when they replaced a ball joint and they had noted a "small leak in the CC" so, in the end, I can live with $1600 for a new CC and 02 sensor. Most importantly, my old 850 is alive once again.

Thanks for all your help!