The check engine light (service engine soon) comes on and stays on when a problem is detected by the self diagnosis system of your vehicle. Generally, the problem is in the emissions or something that is affecting the effectiveness of the emissions, but other causes can trigger the light to come on, too. To determine the cause, the vehicle will need to be taken to a parts store or a shop that has an OBD2 scanner, or for 1995 and earlier models, an OBD1 scanner, While a scanner will not give you the magic answer, it will give you a code that narrows down the problem area.
Check the EGR vavle
Depending on how far off, runs rough, check engine light, no start, engine damage.........
the check engine light is blinking and my 03 Nissan exterra is running rough
Check engine light, low power, no start, runs rough, bent valves,Check engine light, low power, no start, runs rough, bent valves,
and what code does the check engine light say ? go by autozone they will check it for free and get the code.
Auto Zone will check your engine codes for FREE. Then go from there.
A faulty gas cap could cause the check engine light to come on but it would not cause a rough idle or engine noises. Start with having your local auto parts store read the codes. The codes will help determine why the check engine light is on.
If your check engine light is blinking that means an ignition misfire has been detected
Check the engine oil, sometimes when the oil is low the check engine light comes on while sitting still and goes out when you accelarate.
have vehicle scanned to determine the problem
Depending on the vehicle the check engine light would illuminate.
A vacuum leak, a bad injector and if the check engine light is on, check the codes.