My 2000 Chevy Silverado is having massive problems with the dash board. It looks like a Christmas tree, all warning lights will come on and off, the speedometer and other gauges will drop to zero and back to normal every 3 seconds. The dash board flickers and makes clicking sounds. I also have discovered that the truck will not pass smog due to the check engine light coming on all the time, and 3 sensors activating. Please, only serious mechanics answer, thank you! I would appreciate any help at all!