1996 Protege PCM Problems

[jrcox2]

Please HELP!!! Bought a wrecked 1996 Protege LX 1.5 5-speed. Fixed it up and drove it to work on the highway the first day and it overheated. Milky oil. I was working at a salvage yard, at the time and they had a separate garage, so they put a used engine in it. It also needed a PCM. They put one in it and I tried to get it to pass the state emissions test and it failed. They said none of the sensors were set and told me to drive it around some more to set the sensors. 400 hundred miles later I took it to a shop that flashed computers and he charged me $50 bucks to tell me that this computer could not be flashed as it was preset. He suggested I go get another computer which I did..another $60 bucks.

After driving around for another 200 miles I stopped by the Mazda dealership and asked if there was something that I was doing wrong and they said "you just have to drive it around enough to set the sensors." I asked if there was some special way I should drive it and they said "we don't know and if there is Mazda doesn't even tell us." The dealership did take it in and test it and told me I had a weak rear O2 sensor and my catalytic converter should be changed also. I replaced the rear O2 sensor and noticed the car running better but still no sensors would set.

So I took it to a neighborhood mechanic and he got on the phone with his "Mazda Expert" buddy and right away he came up with driving procedures to set the sensors for 1996-2000 Proteges. They are not hard but after spending a whole day almost driving up and down the highway, with a tester in hand checking every time I tried to set it, I took it back to him and he said everything checks out and they should set.

He talked to his expert friend again and told me to get a computer with Z525-18881 on it as I have a Z524-18-881A and he said that my door and my dash VINs don't match. I looked and they do match and after checking on Ebay and other re-builders of ECMs I find that this is for automatic car and it will not work with a 5 speed. So I call him back, before I buy anything, and he calls his friend and they tell me to get a PCM with Z526-18-881 which I looked up and found it to be a California emission PCM.

Now I think that they are trying to blow me off so I go to Autozone and they actually have a part listing with Z524 and Z525 for my year car but it doesn't break it down for what kind of transmission I have. (they just want you to order off of the part number I have in the car) They also show a Z526 and a Z527 but these are both for California emissions. I then go to the Mazda parts counter and see what they show. They wanted my VIN and their parts catalogue showed that I should have a Z524-18-881A in the car and that the new part number is Z5Z4-18-881, BUT I can't buy one from the dealership as they have not one left at all in the country. Six months ago when all of this started they wanted $500.00 for one, that's why I went to a salvage yard and bought another one.

To my way of thinking the sensors should set and then tell me that the catalytic converter is bad, that is, if all of the sensors are working. Am I not correct? Two different mechanics have had the car and said everything is OK and the sensors should set...but they won't. Something is still WRONG.

It's the only car I have that runs (except my BABY 1991 MX-5 that needs restoring) and I don't want to put on a catalytic converter for $500 and still have the same problem. I don't mind fixing the car but I do hate guessing.

Has anyone have any ideas the sensors that wont set are EGR, EVAP, CAT and one O2 sensor (the one before the converter)? Should I just take it to the dealership and hope it doesn't cost me $1000 and a week to get this thing running?
I know this is long and winding story but it's been going on for 6 months and my tags are expired. I hope someone out there has had, or at least heard of this problem.

All help and/or suggestions will be greatly appreciated. I'M LOST.