Howdy, I have codes P0203 and a intermittent P0300 or P0303. I replaced my plug which was fouled, swapped the ignition coil to cylinder 1 to see if the code would jump, no change. Put a new injector in cyl 3, no change. The wire going to the cylinder 3 injector looked pinched so i spliced in a new connector, no change. Finally, I changed the TPS and that didn't work either. I'm pretty stumped here. My symptoms only really happen when the CEL is on. Before that it drives pretty normal but seems to stutter/smoke at idle. The smoke smells like fuel so its running super rich, but the smoke too is intermittent.

 

You might give this video a watch, its a diagnostic tutiroal for this kind of problem. I've having the same basic issue just P2301. except mine is blowing coils up. If weather permits tomorrow I'm going to be tracing my wires all the way back to the ECU/PCM to make sure I'm not grounding out farther back.

 

Did it end up being a wire or did it end up being the PCM in your case? I'm at a loss.

 

Ended up being the wire, the one that sends the signal to the coil.