Simon Grayson's men completed 12 months undefeated at home in League One but they were well below par, despite naming wantaway striker Jermaine Beckford in their starting line-up.
Wycombe manager Gary Waddock could name only five substitutes and his side fell behind after just four minutes when Jonny Howson's speculative shot from just outside the penalty box found the bottom left corner.
Wycombe hit the woodwork twice in a four-minute spell, Jon-Paul Pittman's drive thudding back into play and a Scott Davies corner striking the far upright.
Bradley Johnson had a header cleared off the line but Leeds struggled to repeat the fluency they showed at Old Trafford and Wycombe equalised in the 63rd minute.
Davies played a long pass to Pittman, who cut in from the left to fire past Leeds goalkeeper Casper Ankergren.