I bought a 99 Intrigue 3.5l a few months back. The dealer told me he thought the timing chain broke because there was a loud bang and you could hear spinning. We tore into the engine to repair the timing chain only to find out that the timing chain was fine. We then put it back together and started it to see what would happen, resulting in it firing up with no problem. about a month later, I heard a bang while driving down the road. now the car will not start, it just spins and backfires. We have since replaced the cam sensor, crank sensor and fuel pressure regulator. Does anybody have another idea to try?