Has anyone had this happen with their Z?

metson

This past Sunday on my way home from church, I noticed that my check engine light came on. I used to have a Mazda RX-8 and it would do that when the gas cap was not on tight. I figured the same with my Z...so I stopped and tighten it. I noticed that when i started it again...it was idling rough and then it smoothed out. As i drove off...it started jerking and got worse so I had to park it. I let it cool off and tried again only to have the same results. The next morning, I called the dealership and had it towed. They were busy so didn't really look at it till Tuesday. They called me and said that the codes were reading a problem with a intake valve selonid(sp). I asked is this a issue with the Z and he said no. It would take a few days to get the part in. About five minutes later he called me back saying that there was another code. He said they were checking with Nissan techs to find out the problem and fix it. When I went by the dealership later that day...they said it was throwing out other codes. They were not sure what the problem was but they were going to find out and fix my car. I have not heard anything from them since and its Friday. Anybody have those issues with their Z?