I used NGK plugs from a dealership. Now when in gear the car starts to constantly jerk when like when I am stopped at a light. I checked all the coil connections and the were OK. I have a 97 GXE w / 58000. The only real complication I had changing the plugs was one of the the rubber boots came off one of the coils. After I removed the boot from the plug, I put it back on coil OK. I then finished replacing all the plugs and drove the car for about 30+ miles with no problem. But after the car was off for a while, thats when the problem started. Any ideas guys? Thanks in advance.