95 Lesabre 3800 engine problem

Vehicle sat for 4 weeks. Vehicle had trouble starting and idiling. Check engine light came on. OBD1 showed codes PO341 (Camshaft sensor signal intermittant) and code PO361 (Elect. spark timing, EST not toggling) I replaced the cam sensor and vehicle started and idled fine with no codes or check engine lights. However, when accelerator was held half way down, engine surged as if the accelerator pedal was being pumped up and down. 3 days later I went to road test the vehicle and had trouble starting and idling. The check engine light came on again and OBD1 revealed the same two codes as mentioned above. Before I purchase another cam sensor, I thought I'd check to see if anyone has had a similar problem. I can't imagine a sensor failing with the vehicle shut off for 3 days??? Thanks for any help or suggestions anyone can offer.

Joe-

i have a problem i lost my key i try taking off the cilynder and start it but the security system activate...can i desactivated know that i found the key but the cylinder is broken?its a lesabre 1992