I have a site I purchased and the previous owner has their AdSense ads on the site already. I do not have an AdSense account and i want to submit this particular site for approval. If and when Google reviews the site, will they frown on the Google ads already on the site or should I remove that guys ads prior to me submitting?
You should definitely remove the guys adsense code before you submit your site to google for adsense approval.
Yes, remove them definitely. But also get yourself setup with adsense, it's a fairly easy and straight forward process, then you could simply change the pub ID and you'd be set. In fact, you might save a copy of the site locally (keeping adsense intact), then make your changes to the site for G approval. Once approved, you can simply copy the pages with adsense back and your done... Changing the PUB number of course.