Hi, i drive a 2006 audi a6 3.2 quattro with 55,000 miles on it. I recently took the car in for the esp fault warning. The dealer told me that it was a sludge problem which caused the light to come on and so they flushed it. Im no expert but wtf does flushing have to do with an esp system? they also replaced the oil but while i was on the freeway today the oil light came on and beeped and then went away. what could be causing these problems