Hi Chammy,
I inherited a site that reported 3,184 crawl errors in MOZ and a significant number of them (nearly 600) were duplicate titles and content. I have that down to under 1,000 total errors and only 86 critical errors. I have seen my ranking grow pretty substantially and in one week had 6 pages increase over 20 positions in rank. I can share the MOZ Rank Report if you would like to see it.
So yes, it does have an impact.