For the last three weeks I have been running the car with the inlet solenoid on the right hand bank disconnected. Except for a slight hesitation under heavy acceleration the car is running fine. The 29cc and 29cd error codes have disappeared although have been replaced by a 2A63 (solenoid disconnected) error but this does not seem to generate a CEL. The car idles fine, no smoke. Brings up an interesting philosophical point. At what stage do you walk away?
Seeing I have bought them I think the next thing I will do will be to replace all the solenoids. Not sure why just replacing just one of the inlet solenoids makes such a difference. Is the solenoid on the left bank still operating?
Once I have done that I will reconnect all the solenoids and see if the misfire (and associated error codes and CEL return). From past experience I think they will.