I have an 05 Dodge Grand Caravan. It's been nothing but headache since the warranty expired. Once again its inspection time and it can't pass emissions. Keep getting P406. Since the warranty expired have had the EGR replaced 5 times. The plugs and wires 3 times, the ECM reprogrammed and replaced, new map sensor, new 02s, the cat. No matter what is done to it the code comes back. The repairs over the last year include all the above listed stuff. Any ideas?