It would be wise to know what you're getting into before you take it to a mechanic. I'm not saying your mechanic is a smartman, but there are guys out there that would take advantage of the fact that you don't know your own car.
When you're done with this process outlined below, post up what you find.
Luckily you have a C.E.L., so you could start troubleshooting it yourself.
Your diagnostic port in the engine bay would be near the passenger side shock mount and look like this:
On the underside of the cover is the pinout diagram for the port, connect terminals TE1 to E1 with a short piece of wire. If the sticker with the pinout diagram isn't there, it's these two pins:
Turn the ignition on without starting and count the flashes on the C.E.L.
If there are no stored error codes, the CEL will blink twice per second without interruption.
If there are codes, it will flash once per second for the first digit, with a one second pause between the first and second digits. If there are two or more error codes, there will be a two second pause between each code group. When all the codes have been revealed, there will be a three second pause and it starts all over again.
eg. Say you have 24 and 31, the 'I" will represent the flash and the "-" will represent the pause.
II-IIII--III-I---(start over)II-IIII--III-I---
These are your error codes to look up.
