The lively substitute, who replaced his manager Gary McAllister just before the break, struck a sweet left-foot shot past Thomas Myhre after bringing under control a deep cross from Craig Pead in the dying seconds.
The point was well deserved by the Sky Blues who had most of the possession in the second half.
A rain swept afternoon accompanied by a strong wind made conditions difficult, but Crystal Palace wasted no time in going in front with central defender Rob Edwards scoring on his home debut after nine minutes.
The Welshman, on-loan from Aston Villa, was left unmarked at the far post to head Tommy Black's in-swinging corner firmly pas Gavin Ward.
But Coventry were not without their chances with Andy Morrell producing the miss of the match when he headed straight at Myhre with the goal at his mercy.
Coventry plugged away and Michael Doyle and Pead both went close, while for Palace Dougie Freedman fired over after Coventry were left open.
Eagles caretaker boss Kit Symons said after the match: "We sat back in the second half, put pressure on ourselves and then switched off at the end.
"I was thinking of coming on myself and giving the lads a bit of a gee-up but hindsight is a wonderful thing.
"Coventry are a decent side and hard to beat, it was not complacency setting in. Still it's four games unbeaten since I was asked to take over and I'm hopeful I can get the job.
"I speak to the chairman daily, but there is no discussion about my future. I will be disappointed if I miss out, but then I've got the opportunity from nowhere. I'm not doing cartwheels at the moment, but the bottom line is if I don't get the job then I'm back with the players."
Coventry boss Gary McAllister added: "We got better in the second half and at the end it was a fair result. Steve Staunton gave us that extra quality when he came on and Steve only returned from injury a few days ago."