SES Light

i have an 01 e39 m5, all stock motor/exhaust/intake, and sometimes the SES light will come on after a canyon run or anything that makes the engine work harder than usual. its not everytime tho, i have had some rough canyon runs and been in high RPM's most of the time, and the light DOESNT come on, but sometimes when i pass someone on the freeway, it WILL come on!
BUT it always goes off within the same day
i ordered a code reader already but i was just wondering if anyone has had any similar instances with their beast
thanks in advance
conner

Just wait until you get your Peake code reader and tells us what it comes up with.