1uzfe rough idle causes?

So i just got back off a road trip and the day after my 1uzfe randomly developed a rough/lumpy idle. It started fine and ran fine for about an hour or so as usual, and then the rough idle began. I took the opportunity to replace the valve cover gaskets, plugs, wires, and air filter. I did stop in indiana at the last stop for a last gas up and though i got bad gas from the station. After replacing all of the above it still has a lumpy idle like i have cams in it. During driving it will sputter a bit upon initial take off from a stop then if I maintain a smooth slow acceleration it will begin to break up around 40 or so. Tomorrow i am going to look at/clean the throttle body and take a look at the TPS, and follow this tsrm [url]http://soarercentral.com/sc-forum/me...739/33074.html[/url]. I am beginning to think i might have a dirty fuel filter, injectors as #3, and 5 plugs were fouled, or a failing fuel pump. Any other suggestions, info, or experience with the issue is appreciated, thanks in advance.

i had something similiar with a check engine light on my gs400.  turns out theres a filter for the oil pressure sensor for the vvti or something i cant remember the code cause this happened bout a year and a half ago.  but what i did was used some seafoam, its a cleaning agent, and changed my oil like 3 times and also changed out the spark plugs and it cleared it all up and has been running great since then.