on my way to work this morning my brick shut down on me, took a few cranks and a backfire to finally start it up so I could limp home. Idle's been a tad rough, she studders if I tap the accelarator, sometimes even stalls......

thinking it might be a vacuum leak I tightened the intake manifold bolts (which were a bit too loose) and that made the idle a bit smoother. It doesn't stall if I tap the gas but it still knocks a bit.

I did a quick check of the EZ diagnostics and the code 2-1-4 came up; according to the Bentley manual this is "speed sensor signal bad or no signal," is this the speed sensor on the flywheel? Last time I forgot to plug the wire from the sensor to the harness (after dropping in a replacement engine), she wouldn't start. Am I getting the codes wrong?