Several causes of the car engine problem may relate with the car engine problem. The problem of the P1856 Code may come from the choke plate of the car engine. You check the position of the part correctly or not. You also check the plate is still working or not. Does it open totally or not? If you find any problem in the car engine related above things, then you either change it or repair it. If the parts damage is quite unadorned, I advise you put down your overhaul tools and start observing around for a additional choke plate to circumvent a replication of this horrible episode.