I had a problem with the secondary air intake system recently and mechanic tried many things including sealing the area around 1 inch right under the ECT sensor. (I have 2001 A4 1.8T Quattro auto). However, the problem was in the intake valve. Now I'm wondering is there suppose to be some kind of intake "hole" right under the ECT sensor that I should "unseal"? I am worried because car performance dropped a little and the sensor doesn't work anymore.