Car won't start after filling up with gas

[Rector]

I'm trying to help my father-in-law out with his Volvo S80. Here is what is happening:

1) The car wants to stall when it is started cold. You need to give it some gas to keep it going. Car runs fine once warm except for #2 below.

2) After filling up the car at the gas station, the car won't start right away. It may take 5-6 attempts to get it started.

3) The check engine light is on. We went to Auto Zone but they said they could not tell us what the code means as it is a "dealer code". Need to go to Volvo

I looked all this up on the internet and was convinced that the purge valve was bad and needed to be replaced. However, when I looked at the purge valve it looked brand new! I asked my father-in-law and he said the shop recently replaced a "sensor". I'm sure they replace the purge valve! I seriously doubt the new valve is bad?

Any ideas?

[ThommyKent]

Without a code you are looking in circles. Get a code reader which gives you the "dealer" codes Auto Zone wont. Like an i906 from iCarsoft for $130.00

[Legofan]

I have this and it works great, all you need is a smart phone or tablet and download the Torque app(or similar, I use Torque)

http://a.co/35hTFXH

It will read codes and clear them as well as an explanation of what the code means.