i have a 2003 3500 with the duramax diesel. it started smoking out the tailpipe. took it to the dealership to have it tested. milage is 178000. there was a special extended coverage due to bad injectors. I paid for this test twice, almost 200 each time, my report says, 1 injector is sticking open, 2 injectors slow to open, no injectors leaking. I'am not the smartest guy in the world but if you have a water faucet that won't turn off, you have a leak, brain surgery or rocket scientist, ? Been told by 3 mechanics that the only way it... read full review »