Boost Gauge Issue

[samps]

Hey, just installed my gauges.

I have come into a slight issue, the gauges are electronic not mechanical.

when I put the accessaries on the boost gauge does not sit on zero, sits on -0.2bar.

I have read somewhere that you can fix this by putting something in the sender line to the boost gauge.

the problem I have is I cant remember where I found it and what the thing is called.

Any help???