Do you mean pcm or ecm Emission control module? A code 42 is a crank angle sensor and that says to check for a faulty connector or circuit. also an improper air gap in the distributor. The module in your distributor I believe goes to the ecm so there could be several potencial problems. The ecm unit is the silver box located unde the dash near stearing collum. I also seem to recall reading some where that a connector to the ecm can get loose and cause intermintet starting failers and cleaning the proper connector will sometimes fix the problem. Maybe some one here can give you better details . Good luck