Except for the final two minutes of the second and fourth quarters, coaches can dispute any play. Pass interference has been added to the existing list of plays that can be examined by the booth in the second and fourth quarters in under two minutes. The crew chief will signal either an interference or a catch. If it's a call that can go either way, the referee makes the decision. In addition, during each time out, the coach is allowed one substitution. This substitution may only be made if there is an injury to a player on the field. A player is considered injured if he is unable to continue without assistance from another person. Substitutions may also be made if a team wants to replace a player who went into the locker room for some reason (reportedly, this has happened several times). Finally, coaches are able to challenge any play in the final two minutes of the game. On these challenges, the crew chief will signal either a foul or a touchdown. These are the only options that coaches have during a game. Coaches cannot decline any challenges, even if they believe they are unfair! In conclusion, yes, you can challenge a play in the last 2 minutes of the game.