It was probably a fair result as Coventry looked dangerous up front and deserved their late goal.
Coventry had the first chance in the first minute when Clive Clarke had a 20-yard shot which went straight at Preston keeper Carlo Nash.
In the 15th minute Preston lost Sean St. Ledger to injury and Kelvin Wilson had to come on.
Paul McKenna saw a 30-yard shot from inside the left channel easily caught by Coventry keeper Andy Marshall.
Dele Adebola was booked for a foul and Colin Cameron hit a 20-yard shot which Nash had to dive low to his right to save.
Patrick Agyemang had a 20-yard shot which went wide of the left-hand post.
Preston opened the scoring in the 35th minute when a great cross from the left wing by Danny Pugh was met by David Nugent who headed into the top right-hand corner from ten yards.
Simon Whaley had a 15-yard shot tipped around the post by Marshall and Cameron had a shot deflected for a corner.
Darren Currie forced a save from Nash when he had a ten-yard effort from the left and Agyemang had a powerful shot which hit the crossbar after 63 minutes.
Coventry boss Micky Adams made a double substitution withdrawing Leon McKenzie and Cameron for Stern John and Jay Tabb, while Preston manager Paul Simpson brought on Lewis Neal for the on loan Tommy Miller.
Elliott Ward was booked for handball but Adebola equalised with ten minutes to go when a Clarke pass found him on the right and he cut inside to hit a ten-yard shot into the bottom right-hand corner of the net.
Substitute Tabb was booked for kicking the ball away right at the end but a draw was a fair result.