ok.. Check engine light came on October 2005. took it 2 dealerships and my mechanic, nobody could pull up codes on the computer... 1 dealership ran a diagnostic and said my tranny had 2-3 months to live.. but i just got it rebuilt december 2004, so how can that be... anyway, it felt the same, so mechanic just switched light off..and my tranny's hasn't died..
now june 2006, light comes on again, take it different dealership and again no codes come up...and since I have to buy new battery, mechanic just switches light off.

any idea why the check engine light has come on, even though I feel that the car still runs the same...

 

you did not include model and year your car is. if it was before 95 you can pull the codes youreself, which is easy. if it is after 95 you have an obd11 computer and you need a code scanner. should be able to borrow for free from somewhere like autozone. i have checkers here they let me scan codes in the parking lot for free

 

it's a 96 accord lx. I took it 2 Honda dealerships and also to my mechanic, and none of them pulled codes on their computers.. Should i try to do it myself

 

My local O'reilly store lets people use their code scanners in the parking lot too. You could try that, although I'm not sure what good it would do if 2 dealerships and a mechanic couldn't find anything. Worth a try though.