tune-up screw-up

Hmh! Does it have coil packs? I bet. I'd say its a coil pack problem? Did your replace them? If not, you could have damaged one while removing... or the boot is damaged. If not. make sure that all the plug wires are seated FIRMLY on the plugs... If that doesn't fix the problem, take it to autozone or a mechanic and have them read the code (I assume your check engine light is on) and narrow it down to the cylnder that is misfiring.

Then run a diagnostic check on the ignition of that cylnder.

or remove each wire individually, look to notice which of any makes no difference on engine performance when you pull them one at a time...each one should make it significantly worse as it adds to the misfires....if it is misfiring, the check engine light WILL BE BLINKING, OR FLASHING. personally maybe knocked a sensor, removed a line from the idle, or not plugged back in the throttle, air box hoses....

Thanks guys. yes it does have a coil pack. I'll check it tomorrow.

Did you gap the spark plugs or just put them in as they came? I would set the gap to whatever is optimal for your engine.

Is the car running worse now than before? If it is it could be the wires. If you still have the old ones, swap them out one at a time to see if it makes a difference. It's the easiest thing to do. Then check the gap on the plugs.