Shakes or Wobbles problem
1996 Chevy Lumina 6 cyl Front Wheel Drive Automatic 169K miles
I have a '96 Chevy Lumina that just had it's spark plugs and wires replaced.
Prior to replacing them the car ran a tiny bit rough, and I attributed the problem to needing new plugs and wires. After replacing them the car is shaking back and forth pretty good while idle (in park) and seems to be missing while driving.
Double check if the plug wires are fully seated on the plugs and the cap/coil side. If okay could be caused by the following.
Engine misfiring can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.