Hey everyone,

I have had my 2001 Olds Alero for well over 6 years now and it has been having problems since a year after I got it. Over the years things in the car have been messing up. First it was the automatic locks and the dome light. Then it was the security light and the 'service vehicle soon', 'trac off', 'service engine soon', and the ABS lights would all come on simultaneously. I thought this kind of odd and I began some research. Where I worked, they had AllData which I utilized to get the wiring schematic for the instrument cluster. All the wires go through the BCM including the wires for the dome light and automatic locks. Just a few weeks ago the car started up and shut off immediately. I went through the diagnostic steps for that symptom and found out that the ignition module is working, I installed new plugs, and changed the crankshaft position sensor just in case, and the coils were reading correct. Still the car does not turn on. Thinking it could be the BCM I got a used but working BCM from the same car and installed it and nothing. I have looked on numerous forums for maybe a possibility that it may the PCM and I found one. I am wondering if my problem is an outdated PCM. Everything is stock and the fuel system is not clogged and is working. One more thing, I checked when the lights were on the dash for codes and one was always there PO420-dealing with a catalytic efficiency below threshold. After I replaced the BCM there were no OBDII codes. I am completely stumped. I am a college student with no car and I have to pay for graduate school so I have no real money. Any help would be appreciated. Thank you. Sorry for the long story just trying to provide all the details. Thanks in advance for any help.