Check Engine light

[-viscid-01-GT-]

Hello. About 2 months ago, i hydroplaned on the freeway doing 90 in the fast lane on somewhat bald 255/40 tires. All that happened was it pulled me into the center divider of the highway, which is gravel dirt rocks grass bushes that sort. I was able to slow down without losing control, but i came to a stop on a rock which banged up my cats. a bit. Nothing else happened. about 2 1/2 weeks later i make my custom ram- air intake, which works fine. There were no problems until about 2 days ago when my check enginge light came on. I know this is an emission problem, but out of nowhere it came on. Should I replace my cats. take out the ram air, or could it be som alterior reason for causing it? Thank you for input!!!