A supposed full service diesel shop... I called and specifically told them that I had a 2000 GM 6.5 TurboDiesel that runs strong but idles erratically. They said no problem. After a full week they called to tell me to come pick it up because the computer wasn't throwing any codes at them. They did not want to further troubleshoot the problem and asked me to come pick it up because (all of the sudden) they "don't really work on these engines". Apparently, the skill level with diesels at this shop is limited to the computer telling these guys what to do.