Just got my very first brand new used 2005 Acura RSX a few months ago. Unfortunately my yellow emissions light went on today. I accidentally and very slowly backed out of my parking spot and didn't notice that I was backing off the curb. Its a very low curb, but never the less when my back tires went off it, I felt and heard a thud come from the rear center of my car. Instead of proceeding to fully come off the curb with the rest of the car, pulled it onto drive and went back on the curb. No little did I notice my yellow emissions light was on. Not sure if it came on because of the thud or it had been on prior. sorry. I drove home, no issues, smells, swerving, other flashing dash lights, no jolts in the transmission as I drove. kinda freaking out now. when I got home, I parked in the street, looked underneath the rear of the car and didn't notice anything leaking. can someone tell me why this light is on? the mileage is about 145k PLEASE HELP.