We have a 92 Bonneville it has a hard time starting will start then stall and wont start again..... we were told it was the crank sensor replaced it and it still wont start would like to know what else it could be ? We also did the catalityc converter was the problem either we have the code off of it as follows: 17-Spark Reference Circuit, 18- Cam/Crank Error and 48-Misfire diagnosis.