Broken Flex Pipe cut off
Repair Part sized to fit the exhaust pipe
Installed into HHR
Tack Welded while in place
Removed from HHR
Welding Completed
Re-installed in HHR
O2 Sensors reconnected
Error Code Cleared

HHR idles so quietly now I have to look at the Tach to be sure it's running. Cruising noise level low enough to allow normal conversation. Hard acceleration still generates a fair amount of mechanical drive train stuff, but it did that from day one (it is a 4banger after all).

This problem started with a small crack a long time back and progressively got worse with time (think frog into cool water heated slowly to boiling) until it created the ECs.

Total cost: $52 for the replacement Flex Pipe + $100 labor at a muffler shop that knows what they're doing.

If it's not a forum violation to include this info, for anyone in Riverside, CA area, check out:

Jerl's Muffler & Brake
9431 Indiana Ave
Riverside, CA 92503
Ask for Craig