Rear Air

I recently purchased this vehicle. I was looking around in the engine compartment last night and noticed that someone had disconnected part of the air conditioning. I believe they eliminated the rear air by bypassing the rear evaporator core. Is was a professional looking job. The cap they used looked like it was made specifically for this purpose. My question is, do you know of any recalls for this or can you tell me if this is possibley a standard practice on this particular vehicle. Thanks in advance for your help.