Have you replaced the fuel filter yet? You're lucky, the fuel filter on 03 is external on the
frame rail. 06+ is in the gas tank. Wondering if you did a proper relearn when the throttle
body was cleaned. I clean mine every 6 months, prior to cleaning, I remove fuses #10
and #28. This will "reset" the PCM and do a proper relearn of the clean throttle body.
Now, on motor mounts, if AC Delco brand was not used, aftermarkets will crush down pre-
maturely. Transmission mounts can also cause vibration. But these mounts won't cause
the hesitation or rpm variation. Also, on spark plugs, our I6 engines LOVE AC Delco 41-
103 and nothing else. For some odd reason, it's well documented that other brands will
cause mis-fire and just not run right. I've never seen this on any other engine, other than
ours.