1998 Saturn SL2 Hesitates @ take-off, misses @ cruise

My car hesitates at start from a stop, while @ steady 45-55 MPH ocasionally, intermittantly misses. If I have A/C on it stalls @ take-off. NO codes {Auto Zone Code check} or check engine light. I changed the plugs {BOSCH @ 0.040}, wires {AC/DELCO}. I cleaned throttle body. First I used Autolite wires & Boscsh Platinum plugs, The problem was worse so then I put in the other plugs and wires. One place is thinking timing chain {Auto Zone}, Another Large local place is thinking possibly running lean and or sensor problem. They will check this Wed. And can check streaming info. You guys have been GREAT so I trust and really want your ideas. Thanks, KNAPPIE