Is an adapter necessary on a 98 civic? My fm reception sucks!! I double checked it and it seems like it is plugged in ok. Channels are coming in but it's still not perfect (or close to a stock headunit)
I had the problem with my last deck also and was really hoping that with a newer one I'd have better results

 

You may have a problem with the ant. or you have an amplified ant. and you don't have the trigger hooked up. 94