Toyota Repair: 99 Toyota Solara check engine light, transmission fluid change, coolant levels

Question
I have a 99 Toyota Solara V6 with approximately 75800 or so miles on it. I just recently got an oil change done at a Toyota dealer and coincidentally on the same day a few miles later, the check engine light comes on. It never has before. I checked the oil and coolant levels which are fine, and I have no apparent problems that I can tell. Is it something possibly the dealer did or maybe cuz it's over 75000 miles? I haven't gotten a "75000 mile checkup" but I got a transmission fluid change at 66000 miles. Another note, when I got the transmission fluid changed, the mechanic ended up "making" his own gasket to keep the repair price down. The toyota dealer says the gasket has a slight leak, and said that it's not a big problem but should be replaced...when i checked transmission fluid levels, they were fine. Anyway, sorry for the long explanation, any help on the check engine light would be appreciated.

Answer
I can only help with the check engine light if I know what the trouble code is, some autoparts stores will help you do this at no charge, I think Autozone does this, try to locate one near you, if not you will need to take it to the dealer or to a repair shop that can at least retreive the trouble code from the computer.