Car Idling Rough and Check Engine Light On

What it Means

When your car is idling rough and the check engine light is on, it means that there is a problem with your engine. The rough idling is likely caused by a problem with the fuel mixture, ignition system, or air intake system. The check engine light is a warning that there is a problem with the emissions control system.

Causes

There are many possible causes of a rough idle and check engine light. Some of the most common causes include:

* Vacuum leak
* Faulty spark plugs or wires
* Dirty fuel injectors
* Clogged air filter
* Bad oxygen sensor
* Faulty mass air flow sensor
* EGR valve problems

Symptoms

In addition to a rough idle and check engine light, you may also experience other symptoms, such as:

* Stalling
* Hesitation
* Poor fuel economy
* Increased emissions

Diagnosis

To diagnose the problem, a mechanic will need to perform a diagnostic test. This test will involve connecting a scanner to your car’s computer to retrieve the trouble codes. The trouble codes will indicate which systems are malfunctioning.

Once the mechanic has diagnosed the problem, they will need to repair or replace the faulty components.

Repair

The cost of repairing a rough idle and check engine light will vary depending on the cause of the problem. However, you can expect to pay between $100 and $1,000 for the repair.

Prevention

There are a few things you can do to prevent a rough idle and check engine light, such as:

* Get regular tune-ups
* Change your spark plugs and wires according to the manufacturer’s recommendations
* Clean your fuel injectors every 30,000 miles
* Replace your air filter every 12,000 miles
* Get your oxygen sensor checked every 60,000 miles
* Get your mass air flow sensor checked every 90,000 miles
* Have your EGR valve cleaned or replaced as needed

By following these tips, you can help keep your car running smoothly and efficiently.

Additional Information

Here are some additional resources that you may find helpful:

* [National Highway Traffic Safety Administration (NHTSA)](https://www.nhtsa.gov/)
* [Car Care Council](https://www.carcare.org/)
* [Automotive Service Association (ASA)](https://www.asa.net/)