FWIW, when I first got my Sidekick and did plugs, wire, cap, rotor, it wouldn't start. It'd crank, but would never catch (e.g. run). I checked everything. I did get a CEL, which I checked the code for. It was an ignition issue. I found out that one of the wires to the ignition coil had come loose. Made sure it was attached properly and haven't had an issue for years.