It happens frequently and not really a big deal. Warm your car up before you drive... especially if you have aftermarket exhaust. There can be up to 1 liter of condensation in the system, which needs to get out, otherwise it throughs the warning light. However, once the warning light is on, you have to run the car for a while as once the computer has re-run the system check 5 times w/o codes, it will reset and the warning light with disappear.