llcoolpass

george_jet, it could be the timing except the car would prob have compensated for it. but it could be a few of these things too in the order I think of likelihood:

1clogged egr passage [probably downstream of the egr valve]
2oxygen sensors [check for laggy sensors that haven't been flaged by ecu but are still bad]
3air intake tube or intake manif leak [vacuum leaks]
4fuel pressure/injectors
5spark/- plug issues
6cylinder compression in some cylinders different [head gasket/valves/rings/etc]
7coolant condition/clogs/air bubbles/water pump function

edit: I see a second page I didn't see before, so I now see others suggested some of the same stuff as me, so that's somethign to notice and maybe you will find the problem very quickly

edit2: george_jet, the air meter mod would have the potential to do that, it's funny you say that because I was thinking of adjusting mine back a little before my inspection [haha], but my guess is that the 1mz-fe 's don't have that style air meter. he said 1994 so that's the first iteration of the 1mz-fe and I think they would have the hot wire, I could be wrong.