Thanks for the info. I went to AZ and found there cap was not even the correct one. Also, I found that their loaner pressure tester pump would not fit my Aveo5 either.
I called around all the local parts places and no one has a 17 PSI cap. I guess it must be a dealer item and I’m sure that's going to cost $$. I will call them tomorrow.
I’m not sure what else to do without the proper test tools. I hate to spend money on a cap if it is not needed. Any ideas?