P-22 is a shift lever malfunction code it is either not seeing a signal for 2 seconds from the shift lever or it(the computer) is seeing both a forward and reverse signal at the same time from the shift lever switch.......sounds like the assembly needs to be replaced.......have to pull all the plastic from around the steering column....pull the steering wheel then the Combination switch assembly is held on with four screws...isn't to hard have done quite a few of them myself....bolts for pulling the steering wheel are metric thread(M8X1.25) make sure you screw them fully in did have one that gave me fits and had to reap the threads for new bolts....the steering wheel pulling is the hardest part of the whole process they can be really stuck on good....