Notice much change from slightly narrower bars?

[daninplymouth]

Lately after an hour or 2 on my bike Iv been getting a bit of pain in my neck/trap. I have had a fit and my positioning is fine apart from this little niggle. Iv just remembered I had this issue on an older cannondale when running 44c-c bars I think then I swapped to 40cm but can't fully remember.
I was going to order a new bar to try on my current bike but not sure if I went down to 42 it'd be enough of a change to improve things, or is 2cm enough to notice?