My daughter's 2004 AWD Vibe died while she was in Kentucky. Local mechanic said it was bad cam shaft sensor, he replaced, she drove around town for a day (short trips) after repair, no problems. She left Kentucky headed for home (New Jersey) and the car died after 2 hours in West Virginia. GM dealer diagnosed it saying ECM needed to be replaced but would take a week to get the part. She needed to be back in school so we rented U-Haul with transporter to tow it back. Local mechanic said computer was fine, cam shaft sensor blew out again, stated Kentucky mechanic used aftermarket sensor. After repair he drove car for a few days without issues. My daughter took it back to school, was fine but trips were less than 90 minutes. Friday she got stuck in traffic, trip was 150 minutes and the car died. I had towed to same mechanic, he now concurs with West Virginia GM dealer that ECM needs to be replaced. He can't program a computer, said GM dealer has to do work. Car starts but dies in less than 10 minutes, closest dealer 1/2 hour away. I see used computers on eBay for 2004 auto trans Vibes for $85 delivered. I don't know whether there is something different between that ECM and one for an AWD Vibe. Should I chance buying used ECM to save myself $600 - $800 on a new GM installed ECM?