Sloan made the comments just days after Wells reported earnings Friday of $1.04 a share for the third quarter, slightly better than Wall Street estimates. However, revenue came up light and shares fell.
"We're turning over every rock in the company and we're making really good changes not only to fix anything that was broken but also in terms of investing and making a lot of changes in terms of new products and services," he told CNBC in a live interview. "I'm very optimistic and confident that over time we'll achieve the growth that we've seen historically."
Sloan took over shortly after the bank paid a settlement with regulators over the bank's fake-account scandal. Employees enrolled customers into multiple programs without their knowledge in a practice that affected some 2.5 million accounts.
During a congressional hearing earlier this month, Sloan pledged that Wells "is a better bank" now than it was before the bogus cross-selling practices became public. However, Sen. Elizabeth Warren demanded that Sloan be fired.
Sloan said he was undeterred by the criticism.
"I've got a responsibility to 268,000 team members, over 72 million customers, that's who I focus on every day," he said. "I think I'm the right person to be CEO because of my experience, because of my ability to make change ... and because of the optimism and resiliency that I have and because I have the support of our team."
Despite his assurances that the bank has changed its culture, Sloan and Wells continue to come under withering criticism for conduct leading up to and since the scandal broke. Shares also have underperformed, falling nearly 3 percent in 2017 as part of a weak year for bank stocks overall.
Addressing one of the more specific complains about the bank's conduct, Sloan denied that the Wells hierarchy hid the cross-selling scandal from customers and regulators, despite memos indicating that officials were aware the Los Angeles Times had been talking to disgruntled customers.
"That wasn't elevated to senior leadership, including me, until late 2013," he said. "We had an incentive plan in our retail bank that drove inappropriate behavior. Since I've become CEO we've dealt with that."