Hello ! I desperately try to bring the CO value in increased idle to the required 0.3%, because the TüV denied me the badge without passing AU. I have already renewed all seals, new shaft seals, new exhaust manifolds (the old one was about 10cm torn), KAT is not 1000km old, LMM about 3 months old, new candles, throttle valve cleaned… Ommi does not jerk, lies super on the gas, no dropouts, idle quiet and constant at approx. 700upm, No cold start problems o the so. There are apparently no negative signs visible…?! Vehicle data : Omega B Caravan, year 1995, motor : X20XEV, mileage : 230,000km Idle CO – 0.363 – i.o. increased idle CO – 0.572 – n.i.O Lambda – 1.022 – i.o. control circuit test Basic procedure 2 deflections – i.o. initial value ^1.015 / interference size detected / ^excluded 1.029 / interference size detected / ^excluded 1.017 The CO value in the increased idle is not below 0.5 The only thing I have not yet replaced e is the Lambda probe because I thought if the control circuit check is fine, the probe is also fine…. – or am I wrong there..? But since I can’t think of anything else I will replace the Lambda probe tomorrow, no idea if it helps…. – quite expensive attempt..! Does any of you still have advice ????? Thank you and greeting ! Dirk