Help needed with clearing off not-found pages

I experience weird SEO problem as google has once indexed ~500 pages with sample products while new cs cart was installed and kept on for awhile so now google bot loves to find 500 of 404 errors on every reindexing. But i think it’s bad behavior.

I have submitted sitemap and requested reconsideration of the site few weeks ago. No little progress since that, no traffic, no joy of live.

If anybody can help me with rewrites of the old staff that mostly has a small pattern (vote=). I am not just sure if that is enough to do the job. This is example of ‘missing’ page:

[url]Hot Yarn HotYarn

There are also sample pages like this [url][/url] which i know for sure that i dont know how to deal with.

If this same problem met before, please share the information with a thankful man like me.