code P0410 HELP please!

[volvo960sw]

, 1997 Volvo 960 sw, 203K+ miles
Hello all,
It passed Calif smog inspection this past Jan with good numbers. Last Friday morning the CEL appeared and O'Reilly auto parts pulled the code P0410. Secondary Air System Fault/ Vacuum Leak. Upon inspection, I discovered all elbows tubings connecting to the SAS valve, SAS control solenoid valve, intake manifold tree, vacuum line couplers, vacuum check valve, etc...are all breaking up. So I replaced them all and reset the CEL by removing the battery negative cable for about 15 minutes and reconnected. The CEL was gone but after being driven almost 100 miles this afternoon (almost 90 degrees F) the CEL came back.

Question:
1 Resetting the fault by removing the battery's negative is the right way to do or get to use OBDII to erase it?
2. What can I do next to fix this problem?

Note: noticeably better acceleration after all the elbows were replaced.
Thank you all,