Hey, short question to our Pro ́s here in the forum. I had the original SAAB engine control unit for my 2.0l eco turbo (with approx. 200hp) installed with new injection valves and spark plugs at my SAAB dealer before about 20Tsd Km. Now I wanted to ask: 1) when should the ZK be changed (interval?) 2) which are the best ones? The SAAB recommends (are the standard candles, ..I believe..) or is there Bosch or BERU ZK that are better (wherewith the question would be, what is the best? thanks and greetings from Berlin Konstantin