Late to post but I wonder if this has been solved? I did not see anyone mention the MAF sensor; they get dirty, they go bad and can cause all sorts of problems. Also you can check the wiring to, and the actual coolant temp sensors- if it runs better when hot it may be an issue with that.
I’ve worked on a variety of PRV engines for over 15 years now, I’ve seen them click past 200,000 miles. I find them to be extremely reliable – never have I once been stranded by a PRV powered car. If you start with the regular maintenance items and take care of them, they will last a very long time.