service engine soon light

What is your question?

a day after a big snow storm i started car to move it, ran fine after shoveling snow started car to move back and noticed it was rumbling a little and service engine soon light was on. looking in manual syas it has to do with emissions and possible exhaust overheating. after i shut car off, i noticed there was snow encasing the bottom of engine. started car again light remains on but pedal has slight hesitation at top but is very smooth after that.is it possible yhe snow may have loosened a vacuum hose or would it run rough all the time. any suggestions greatly appreciated. tom