Pontiac Repair: Multiple sensor failures, pontiac sunfire, gas cap

Question
I took my '97 Pontiac sunfire GT (2.4l) in to have it smogged.  The check engine light indicated that 3 sensors need to be replaced: o2 (front), crankshaft position, and the throttle position. Additionally, the gas cap failed. When I took it to my mechanic, he suggested that we replace the o2 sensor and wait to see if the rest clear.  He said that he had never seen all three sensors go bad.  He also thought that there may be a wiring issue.
Would you have any comments or suggestions?  And is it possible that the faulty gas cap could have anything to do with it?

Answer
Follow up , No it doesn't matter who owns the car or how many miles there on it. if has never been done then thye will fix the recall issue free of chage it's not to say that it will fix your problem but it's worth a shot.

Hi Derrick:

That is a bit odd. )2 sensos on this car are pretty common though. the gas cap going bad is common as well. The other issues are not common. A bad gas can is not going to cause sensors to go bad. I would suspect a bad ground connection for the ecm or even a bad ecm. this car had a recall on the ecm I don't know if it was ever done. the recall was for water intrusiion into the ecm harness and ecm. you may want to call your local dealer and give them your VIN # and ask them to run the # and see if was ever done. Good luck :}