miss or stutter 5.3 4X4 (106K)
 

had a slight miss or stutter between 45 & 55 MPH when at steady speed. Time to change plugs and wires any way so I did it this weekend. Now miss is worse and also happens when accelorating easily in the same speed ranges. Any Ideas??????????

Are you getting any codes? Has the throttle body been cleaned recently, if not it is basically a free (besides a can of throttle body cleaner) preventative maintenance item.

no codes, no check engine

Then if you haven't already I would clean the throttle body real good along with the IAC (which is also in the throttle body) and see how it runs. If it still is not fixed I would start testing the sensors.

Like speed sensor, o2 sensor, coils etc.

excuse me for being stupid but what is the IAC???????

Idle Air Control Valve - it is screwed into the throttle body. Also a bad TPS (Throttle Position Sensor) could be going bad without throwing a code.

If I get some one to plug a computer into to it and make it duplicate the problem will that narrow it down possibly. I have a guy who has a shop and is pretty good but not cheap but I trust him!!!!!!!!!!

If he knows what values to look for then yes he should be able to determine the issue. Good luck!

thanks for your help shamrock