2003 buick park avenue misses badly on acceleration or hill climbing. ZSpark plugs show burn lines on ceramic part replace and it reoccurrs

Did you also replace the spark plug wires? The burn lines on the ceramic would indicate that it's jumping fire. Are the burn lines on ALL the plugs or just one or two? If you look closely at the wires in the dark, you will be able to see the spark jumping to ground if the wires are bad. If you have already replaced the wires and still have that issue, it's possible that you have a bad coil pack or ignition module.