Maybe I'm just spoiled... SLIGHT VIBRATION

I've noticed lately when I stop at a red light, with my foot on the brake, I can feel a slight flutter from the engine. It used to be that when stopped, I could hardly even tell the truck was running. There are no CEL's coming on or anything, and the truck runs and drives great. Am I just spoiled or could there be a reason for this? 2007 with 54,xxx miles. Thanks.

Could be lots of reasons I would guess.......
AFM kicking in to 4 cylinder mode?
Dirty MAF sensor or fuel filter/injectors?
Plugs or plug wires old?
Loose or cracked motor mount?
Maybe even a brake issue due to to worn disc or pads or ABS acting up?
Or you are getting old and muscles and nerves in leg isn't what it used to be....  

injectors could be dirty. When was the last time you use injector cleaner?

Think it's been about 8-10 months since I used injector cleaner. Tell you the truth, never had much faith in the stuff.

Couldn't be the afm kicking in...I have that disabled.
How many miles do they suggest before you replace plugs and wires?

My legs are not what they used to be, that's for sure.