Go to your passenger side, pretend your sitting in the seat. Pull back the carpet underneath and to your immediate right of the glovebox. Right under the right part of the glovebox, you'll see a green rubber thing. Pull that out (it may be taped to something) and there are 2 harnesses within it. Take the smaller one out (2 connectors, and taking it out can be very tricky) then take a paper clip and connect the 2 wires together, you won't get shocked... Now make sure it is in there good and turn the car to the ON position (not start) and you'll see the check engine light strobe. Long flashes indicate the tens number and short flashes indicate single digit numbers.

Say it flashes 2 long flashes then 5 short flashes...it's 25... the bring us back which number you got from it. But you may get numerous numbers, if it doesn't repeat the number '25' over and over, you have more than one error. Take the paper clip out and return it to its position.