They're getting on your good side so they can slap you with an enormous bill later.
The computer does have a lot to do with how almost everything works thruout the PT. Lets hope you don't need a new one but the way a lot of shops work nowadays, they just throw parts at a problem in hopes of curing it. You can tell that by the way owners come here and tell us that the shop replaced this and that at a cost of $$$$ and they still have the same problem.
I just found this searching for help in another thread. This highlights what i just said......
I have a 2001 pt cruiser and it died the other day. It backfired, the check eng. light came on and it shut down. Mech said it was the cam sensor and the crank sensor. They replaced them for $520.00 but now say that the sensors caused the plugs and wires to be damaged and want more money(300.00) plus, and now say the battery is bad and need an additional (160)plus. Can you help me and tell me if I am being scamed. I have been told that I am.