I recently purchased a 1997 GMC Sonoma with 150,000 Miles on it. After purchasing it I decided to replace and gap the spark plugs, not yet the wires. After doing this shortly after the truck has developed a horrible jerking in low gears, especially first gear. Also while on the highway when I release the gas there is a slight jerk as well for a second. Could this be due to bad plugs or bad plug wires? I wanted to check your knowledge before I tried anything. Thanks!