had a place called american muscle car here in palatine,il.Good people. Had 4 coils go bad . Plugs were bad also. They replaced ,wires,plugs and the four coils. Went to get it friday and after 5 mins or so the car started shaking. Like it was running on 6 cyl again. Is it possible for the other 4 coils to go bad? Car only has 25000 on it. 1999 ls1 5.7 z 28

 

more likely that the plug wires aren't seated properly. they can be suprisingly hard to connect properly. Especially on the rear of the passanger side, where its tough to get your hand in there.

Pull the codes and see which cylinders are misfiring, then check that all the wires and coil connectors are hooked up properly. and I somehow doubt that all 4 coils were bad. wonder if they just condemned all 4 on the same side.