Sunfire no start.

1997 Pontiac sunfire 2.4 with 100k mileage. Drove to work, when pulling onto the parking lot I noticed kind of weird noises coming from inside the instrument panel area. I shut down the car and went to work. Came out apprx 9 hrs later. Car turns over but won't start. An ob2 reading said cam and crank sensors, I have replaced the crank sensor, cam sensor, fuel pump, fuel filter, plugs wires, PCM, I even tried a different computer (in the right front wheel well) all to no success. I finally gave up on the car let it sit for a year. I started back on it last night, I recharged the battery and put the old computer back in, hooked the battery back up and tried to start it and it runs for about 10 minutes, makes that funny noise under the dash again and then dies now it will not run. What is going on. What do I do, helppppp. Thx, todd addendum: we did a check with the ob2 and the codes read PO335 and PO342 hope this helps.