Engine Light on '04 Jag

I live in California and had to have my 2004 Jaguar smog checked. I took it to a smog center and it passed, no problem. I left the smog center and filled the gas tank. After the next start up, the check engine light came on. It sputtered 1x getting on the freeway just after light came on, nothing since (1 week ago). Suggestions have been that an adjustment made at smog check could have affected engine performance and I should have it checked. I am about to call dealer. Your suggestions?