The hosts went into the game seven points off the top six and had a chance to close the gap with a number of teams around them not in action.
But they wasted the opportunity as they failed to spark into life in a disappointing display.
And while Palace did well to frustrate them, by far the most interesting action took place on the sidelines as Sousa was dismissed for protesting too vigorously against a challenge on Samuel Di Carmine.
QPR had won both of their games before the international break and started brightly.
Wayne Routledge, who began his career at Palace and was booed throughout by the visiting fans, played a superb throughball into the path of Liam Miller, who saw his shot saved by Julian Speroni.
The game was becoming a gritty midfield battle, but if there was one man who could provide a moment of inspiration it was QPR's Adel Taarabt.
The Moroccan has impressed during his loan from Spurs and showed just why when he beat two men with two delicious drag-backs before Speroni beat away his goal-bound effort.
But in truth the game was instantly forgettable - although the goings-on in the dugouts certainly weren't, culminating when Sousa was sent to the stands moments before half-time.
It appeared an over-reaction from referee Scott Mathieson after Sousa had rushed out of his technical area when Di Carmine was caught by Claude Davis' high boot.
Davis was booked but Sousa's punishment was harsher as he had to watch the remainder of the game away from the dugout, leaving Gareth Ainsworth in charge.
And Neil Warnock's visitors immediately looked to make the most of QPR's disorganisation, with Victor Moses forcing Radek Cerny to tip over his 20-yard effort moments into the second half.
But QPR came roaring back as Di Carmine and Routledge both went close and they should have taken the lead with the best chance of the game on the hour-mark as Taarabt blazed over from 12 yards after Di Carmine's flick had put him through.
That was the last chance of a disappointing game as both sides appeared to settle for a draw which all but confirms they will be facing each other again in the Championship next season.