WARNING:
Leaving children, helpless adults, or pets in a
vehicle with the windows closed is dangerous.
They can be overcome by the extreme heat and suffer permanent injuries or even death from heat stroke. Never leave a child, a helpless adult, or a pet alone in a vehicle, especially with the windows closed in warm or hot weather.
Chevrolet Cobalt Service & Repair Manual. Catalytic Converter R&R
1.
Raise and support vehicle.
2.
Remove wheel drive shaft heat shield.
3.
Remove Heated Oxygen Sensor (HO2S).
4.
Remove catalytic converter to resonator
pipe nuts, Fig. 1.
...