Q: How do I replace the spark plugs for Chevrolet Cobalt,HHR and Saturn ION?
A: Disconnect the cable from the negative battery terminal and remove the ignition coils. You'll need a spark plug socket, extensions, a gap gauge, and a torque wrench. Buy the right spark plugs for your engine and adjust them to the correct gap. Let the engine cool before removing the plugs. Check the new plugs for defects and adjust the gaps. Use compressed air to clean the spark plug hole. Remove the old plugs with a socket and ratchet. Install the new plugs, tighten them with a torque wrench, and apply anti-seize compound to the threads. Repeat for all spark plugs and reinstall the ignition coils.