My 2007 Chevy Cobalt 2.2 automatic is showing a random misfire and its making a putt putt sound from tailpipe. It is idling rough and is cutting off when I idle too long. What would be causing this? All my scanner shows is the random misfire on 2007 Chevrolet Cobalt 2.2 automatic.
RESPONSE
Chevy Cobalt Check Engine Light
Your vehicle has a computer which monitors operation of the fuel, ignition, and emission control systems.
This system is called OBD II (On-Board Diagnostics-Second Generation) and is intended to assure that emissions are at acceptable levels for the life of the vehicle, helping to produce a cleaner environment. The check engine light comes on to indicate that there is a problem and service is required. Malfunctions often will be indicated by the system before any problem is apparent. This may prevent more serious damage to your vehicle. This system is also designed to assist your service technician in correctly diagnosing any malfunction.
Caution! If the vehicle is continually driven with this light on, after a while, the emission controls might not work as well, the vehicle’s fuel economy might not be as good, and the engine might not run as smoothly. This could lead to costly repairs that might not be covered by the vehicle warranty.
Caution! Modifications made to the engine, transaxle, exhaust, intake, or fuel system of your vehicle or the replacement of the original tires with other than those of the same Tire Performance Criteria (TPC) can affect your vehicle’s emission controls and may cause this light to come on. Modifications to these systems could lead to costly repairs not covered by your warranty. This may also result in a failure to pass a required Emission Inspection/Maintenance test. See Accessories and Modifications .
This light should come on, as a check to show you it is working, when the ignition is on and the engine is not running. If the light does not come on, have it repaired. This light will also come on during a malfunction in one of two ways:
| • | Light Flashing — A misfire condition has been detected. A misfire increases vehicle emissions and may damage the emission control system on your vehicle. Diagnosis and service may be required. |