Hey I think my truck is doing the same thing. I don't have a rough idle, but I do have a delayed acceleration. I replaced my plugs and wires, MAF, cat converter, exhaust, intake, all within the last year or so. It runs really smooth, but it still seems to have a hesitation when I first accelerate "(full throttle, "put put put" then "vroom")"...I had to change my battery yesterday so my car went back to it's original specs (sensors and whatnot). It ran much more smoothly this morning, and there is ZERO hesitation in the acceleration, amazing. Funny thing about the sensors however, if they sense a problem, (ie: too much O2 in the exhaust) they try to fix it by adding more fuel and messing up the a/f ratio. I'm thinking after I drive it for a while, it'll go back to it's crappy settings and i'll be back at square one...I was reading a post on another site that I was considering of doing it since I've never changed my O2 sensors and they're over 13 years old. This is my next option if my car goes to "crap" mode again. Hope this helps dude
http://www.rangerpowersports.com/for...ighlight=p1443