Car is Idling Rough and Check Engine Light Is On

If your car is idling rough and the check engine light is on, it’s important to take it to a mechanic as soon as possible. There are a number of potential causes for this problem, and some of them can be serious if not addressed.

Common Causes of Rough Idling and Check Engine Light

Vacuum leak: A vacuum leak can cause the engine to run lean, which can lead to rough idling and a check engine light. Vacuum leaks can be caused by a number of things, such as a cracked or loose hose, a faulty gasket, or a damaged intake manifold.
Spark plug problems: Worn or fouled spark plugs can cause the engine to misfire, which can lead to rough idling and a check engine light. Spark plugs should be replaced according to the manufacturer’s recommended schedule.
Fuel injector problems: Clogged or faulty fuel injectors can cause the engine to run lean or rich, which can lead to rough idling and a check engine light. Fuel injectors should be cleaned or replaced as needed.
Intake manifold problems: A cracked or warped intake manifold can cause a vacuum leak, which can lead to rough idling and a check engine light. Intake manifolds should be inspected for cracks or warps if the engine is running rough.
EGR valve problems: A faulty EGR valve can cause the engine to run rich, which can lead to rough idling and a check engine light. EGR valves should be cleaned or replaced as needed.
O2 sensor problems: A faulty O2 sensor can cause the engine to run lean or rich, which can lead to rough idling and a check engine light. O2 sensors should be replaced according to the manufacturer’s recommended schedule.
Catalytic converter problems: A clogged or damaged catalytic converter can cause the engine to run rich, which can lead to rough idling and a check engine light. Catalytic converters should be replaced if they are clogged or damaged.

What to Do If Your Car Is Idling Rough and the Check Engine Light Is On

Take your car to a mechanic as soon as possible. The sooner you take your car to a mechanic, the sooner they can diagnose the problem and start repairs.
Tell the mechanic about the symptoms you’re experiencing. Be sure to tell the mechanic about the idling problem, the check engine light, and any other symptoms you’re noticing.
Get a diagnosis from the mechanic. The mechanic will need to perform a diagnostic test on your car to determine the cause of the problem.
Get repairs done. Once the mechanic has diagnosed the problem, they will recommend repairs. It’s important to get the repairs done as soon as possible to prevent further damage to your car.

Conclusion

If your car is idling rough and the check engine light is on, it’s important to take it to a mechanic as soon as possible. Rough idling can be caused by a number of problems, some of which can be serious if not addressed. A mechanic can diagnose the problem and recommend repairs to get your car running smoothly again.