I had a check engine light come on last week and got a code indicating a bad ignition coil. After changing it out, the engine ran fine for a while then began idling roughly. There is no sensation of a mis-fire, just rough idle. Any suggestions? Thanks.

 

How about more information.
What year is your truck?
What size engine does it have?
This symptom could be anything from a clogged fuel filter, bad spark plug wire, vacuum leak, bad gas, clogged air filter.
If you have the bucks take it to a mechanic and have them diagnosis the problem for you.Then fix it yourself.

 

Agree, a bit more info.. how many miles does it have on it...
I would suspect injector, but it could also be idle air control, dirty air filter, bad gas, low fuel pressure, vacuum leak...