In addition to notifying NHTSA (or Transport Canada) in a situation like this, please notify General Motors.
Call 1-800-222-1020, or write:
Chevrolet Motor Division
Chevrolet Customer Assistance Center
P.O. Box 33170
Detroit, MI 48232-5170
In Canada, call 1-800-263-3777 (English) or
1-800-263-7854 (French), or write:
General Motors of Canada Limited
Customer Communication Centre, CA1-163-005
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7
Chevrolet Cobalt Service & Repair Manual. Exhaust Manifold, Replace
Removal
1.
Remove exhaust manifold heat shield.
2.
Remove oxygen sensor.
3.
Raise and support vehicle.
4.
Remove manifold to exhaust flex decoupler
mounting bolts.
...