Saturn Repair: 1993 SL2..Is it the PCM?, vacuum leaks, emissions test

Question
I have a 1993 SL2.  The engine was replaced just before I bought it and I have NO idea where it came from.  The problem I have is I get an Error Code 44.  I have taken it to several mechanics and had all the sensors changed.  It fails the GA emissions test at low speed.  The last person said the PCM was bad.  Does this make sense?  If it is the PCM, will any 1993 pcm work or just one for a DOHC 5 Speed?

Answer
Well, a code 44 is a lean oxygen sensor signal. Before replacing the PCM which is unlikely what the problem is, I would check into a few things. First make sure that there are no vacuum leaks and that there is not a exhaust leak before the sensor. There have been instances of cracked exhaust manifolds which will cause this code. Also the injectors could be gummed up. There is a whole plethora of things that could cause that code. I would replace the PCM as a extreme last resort. And if you do, it has to be from the same engine and transmission type.