Why is my Kia Rio engine idling rough?

I've noticed that my Kia Rio's engine has been idling rough lately. What could be causing this and how can I fix it?

It's possible that your spark plugs are worn out and need to be replaced. This can cause rough idling and affect your car's overall performance. I would suggest taking your car to a mechanic to have them checked and replaced if necessary.

Another common issue that can cause rough idling is a dirty air filter. Check your air filter and replace it if it's dirty. This should improve your engine's performance.

If the issue only occurs when your car is in gear, it's likely a problem with your transmission. I would recommend taking your car to a transmission specialist for diagnosis and repair.

In some cases, a rough idle can be caused by a vacuum leak. Inspect your vacuum hoses for any cracks or leaks and replace them if necessary.