95 stratus - map sensor

Really need some help here, please. I have a 95 Dodge Stratus, 6 cyl. It has 143,000 miles and until recently, running like a charm. It has been dieing whenever I sit idle for any amount of time, Red lights are a definate "two footer" right now. Anyway, when I did the ignition key diagnostics, the code came back referencing the MAP sensor/circuit. I replaced the MAP sensor and all was fine for about 3 days and then it started all over again. I apparently have OBDII 1/2.....ha ha ha.....the local auto parts stores do not have the connection to plug into my OBD outlet so I can get the exact problem code. Can someone point me in the direction of fixing this problem? I really do not want to take an 11 year old car to the dealership to be fixed, they are the only ones capable of scanning the OBD, and they cost $80 just to run the scan. Would rather do it myself, just don't know what to do.
Not sure if it matters or not, but I did overheat about 4 months ago. Had to have the water pump replaced. In the process, I had them to also replace the timing belt, serpentine belt and ac belt. I use the Bosch 4 platinum plugs and Bosch wires. I use synthetic oil and a K & N air filter.
Someone please help this desperate Texas Lady get her ride back up and running right.:banghead:

K&N...I read in an artical, where the oil from that filter can hurt some sencer. sorry, thats the best i got.