Loss of sensitivity, autotune shows 200 peaks

Having problems where autotune shows over 200 peaks.

What can I do?

Are you referring to this value shown below?

Yes

If this value is higer then roughly 130 or so, and the air (28/69) ration is good and all other tune parameters look OK, it means there is a high chemical background in the analyzer.  Best thing to do is to bake out the source at 300C and quad at 200C overnight.  I like to increase the column flow to 3 or so and bakout the GC inlet and column as well.

I allready tried that…

OK, it's also possible a noisy detector can cause this.  I would clan the detector area.  It's very important to blow out the detector area with inert gas.  Small particulates in the detector area can cause "arcing" or creation of fals signal.  Here is a great video on cleaning the HED.