Q: My truck is starting to have a rough idol , I changed the spark plugs about 6 months ago.

The rough idle is often times associated with what is called an idle air control module/valve which regulates the air intake as it is mixed with fuel prior to being injected into the motor. When this is not working properly, this creates an imbalance in the air/fuel mixture which will cause the rough idle you are describing. I would recommend having an expert from YourMechanic come to your home to diagnose the rough idling and repair.

Hi. There may be a vacuum leak somewhere on the engine or loose or broken vacuum hose. A vacuum leak will cause a rough idle and may also the truck to stall and stop running. There also could be a problem with the electronic throttle giving a bad reading to the computer. There may also be a problem with one or more of the coil packs misfiring causing a rough idle. I suggest you have the vacuum checked for leaks and the Pcm checked for codes.