Injector - Is this the problem

[papasmith]

I have a 3.4 engine and it has almost a dead skip.

I have:

Replaced plugs
Replaced Wires
Replaced Oxygen sensors
Replaced MAP

Reading the codes I got:

19 Crank Sensor Fault
33 MAP Sensor or circ to low
34 MAP Sensor or circ to high
42 Electronic Spark Timing Problem
41 No ignition Reference Pulses

The car is running rich and has some soot on the plugs except for the number 1 cylinder which seems suspiciously clean.

My question is, what is the likelyhood of it being a bad injector? What about a coil? The problem came on rather suddenly. If it is an injector, how hard is it to replace and is there a good place to get them on line?
Thanks