Is anybody out there having problems with the Duramax in a 3500 with the Allison transmission engine brake not working and throttle sticking at low RPMs and will not idle down I've taken it in for service they Tell me it's not setting engine codes they drive it and it does what I say it does and they don't know what to do with it and GM tech is still scratching their ass too I'd appreciate any feedback if anybody else is having this problem still under warranty $26,000 mi on it