99 running rough after replacing plug wires

I have a 99 that I just replaced the spark plug wires on. I did them one at a time so not to mix them up. At idle the engine sounds fine, but under load it is running very rough, almost no acceleration. I am going to double-check the wiring again. I am not used to working on electronic ignition computer controlled systems. Does the system need to be retuned or reprogrammed after replacing plugs or wires?

I am going to triple check the wires again and maybe go back to the original wires and see if that makes any difference. Thanks in advance for any replies.

Kranthor.

Replacing the wires is a pain in the first place.
Sounds like you are not getting the amount of spark you need for clean detonation. If you didn't change plugs do it. and don't use the split fire or platunum plugs just the good ol' autolites. I have had a lot of trouble with the "better plug" also look for a boot not all the way on the plug. you can hear a clicking noise there is arcing in the boot, this will degrade power. also turn the lights off in the garage (at night) and see if you see any sparks jumping around. Look at the connection point of the wires. are there any carbon traces...Black lines. if so get some electrical contact cleaner and clean those off. any excess dirt on the distribution block will cause arcing. that is what it sounds like to me. due to the lack of power at speed.
Hope this helps

Thanks for the pointers. Turns out that I did have my wires crossed,literally. I had 1 & 3 crossed. I let the little number 1 engraved in the block by cylinder 3 through me off. I must not have been as careful as I thought I had. Now I just need to tackle the "Trac Off" light problem so I can sell this thing.