Anybody have this problem on their 4th string?

I like a 22 or 23 gauge 4th string--gives me the sound I like. But it also gives me a noticeable metal hitting metal sound when I fret the 4th string, particularly when I hammer on (especially 0 to 4). A thicker 4th string (say 26 gauge) does not do this. It is especially prominent when the 4th string is loose, for example, tuned to C. I also get this undesireable sound with a slide. Anyway, any solutions to this? Anyone tried a particular brand that lessens this effect? (I use mostly GHS, with an occasional D'Addario).