The Arsenal boss says the Gunners must return to their early-season form if they want to secure a Champions League berth.
The Gunners failed to win for the fourth straight Premier League match, and the Toffees now sit just one point behind Wenger's side with a game in hand still to play. And though the Frenchman believes his side has winnable fixtures, the task is certainly a tough one.
"I’m 100 percent determined to fight for the top four but it will be difficult," he told reporters. "We still have a (schedule) that is feasible but we have to first focus on the quality of our performances before we dream of places. Let’s get back to playing better.
"The fight is very open and it’s not just dependant on us, but it depends on Everton, who are in a strong position. We have been confronted with that before and it’s about how we respond from such a disappointing performance."
Wenger's side was poor in a number of facets of its game, and the manager conceded that his side has lost confidence in recent weeks, especially away from home.
"Our performance was not convincing, neither defensively or offensively. Everton were better than us and deserved to win," Wenger said. "It’s a very disappointing result and a very disappointing performance. We have to regroup and come back to basics.
"Today we were behind 1-0 early and I still feel we had a lot of the ball, though we weren’t really dangerous. Everton defended well and at the moment we lack confidence and penetration. The incisiveness from our game is missing."
He added: “I would say our big defeats away from home have taken the charisma away from our team.”