2009 Chevrolet Cobalt Owner's Manual - Page 280

How to Inspect the Engine Air Cleaner/Filter { CAUTION: Operating the engine with the air cleaner/filter off can cause you or others to be burned. The air cleaner not only cleans the air; it helps to stop flames if the engine backfires. If it is not there and the engine backfires, you could be burned. Do not drive with it off, and be careful working on the engine with the air cleaner/filter off. Notice: If the air cleaner/filter is off, a backfire can cause a damaging engine fire. And, dirt can easily get into the engine, which will damage it. Always have the air cleaner/filter in place when you are driving. To inspect the air cleaner/filter remove the filter from the vehicle and lightly shake the filter to release loose dust and dirt. If the filter remains caked with dirt, a new filter is required. Never use compressed air to clean the filter. To inspect or replace the engine air cleaner/filter, 1. Turn off the engine. 2. Disconnect the air flow sensor electrical connector. 3. Loosen the screws on the clamps holding the air outlet duct in place. Do not remove the clamps. 4. Remove the air outlet duct. 5-22