Q: Rough idle on car

Hello. The most common cause of a rough idle on this engine is a vacuum leak. Most of the time this is caused by a loose or broken vacuum hose. With the engine running you can listen for any hissing noises from the hoses to see if one is leaking. If nothing is found then it may be due to worn spark plugs. Most of the time if the problem is not obvious a mechanic will scan the computer for codes to see if there is anything saved in the computer. If there are then that may identify where to start. If not then the computer data from the sensors would be looked at to see if it is a sensor problem as a failing is a dirty sensor can also cause this. I would typically also check to see if the throttle body is dirty. If it is then it should be cleaned first to see if it solves the problem. Have a certified mechanic diagnose your car’s rough idle to have this problem solved accordingly.