Q: P0733, P0734, P792, P490, P1790 after mechanic rebuilt engine

I think these codes may be explained by an electrical harness connector that is unplugged. The first two codes refer to the transmission ratios and the P0792 is for a speed sensor. The lack of a speed sensor signal could be causing the 733 and the 734 codes. code 490 is for high voltage at an EGR sensor which could happen if the circuit is not completed and 1790 is a Chrysler specific code for the transmission control system. So while it looks bad, it may be that all of these codes could be solved by correcting a single electrical connection. Take the car back to the Mechanic and ask him to look it over and see if there is something amiss. Removing and installing an engine involves dozens of electrical connections and it’s very easy to overlook something. If you need another opinion, you can contact Your Mechanic to have a technician come out to your home or office to check out your Chrysler and make a recommendation.