I will have to look up the info on that since it is for an SN and there may be differences (it is SO unlikely, I will hold off. You are not spitting the right code for it. Since the SN's have better processors, it would likely spit the correct code).
Otherwise just make sure the valve is really clean and that all the connections are clean and good to go. A bad ground on the EVR connector will toss a limit code (which you dont appear to have anyhow).
Those passageways should be fairly healthy - a straight brush should remove carbon in the 90* bend (I did not have one of those brushes on hand so I could not clean it as well as I wanted. A toothbrush does not fit down one of the passages very well).
In its dynamic, you should be able to check the values at the connector (VRef, signal, ground) and make sure the right signal are being sent. At that point you can see if the sensor is calibrated too (see if the signal reading is off)
Though the passageways many not puke out lots of filth (mine didnt), cleaning can 'unhang' the pintle's movement. There is not much vac to that diaphram, so getting it unhung is important (so it actuates real smooth). That really might take care of it.
Good luck.
