Ok. I will check all the vac hoses this weekend. Will probably pull the throttle body and check for holes in the boot. Probably needs a good cleaning anyway. Preparing for coolant crossover gaskets in the future. Dealer that I purchased the DHS from recommended them being done. Been watching coolant levels like a hawk. No changes in 3K miles since I purchased it. So far so good. Engine has a very rough idle on cold and warm startup that goes away in a few minutes. No missfire codes showing. Maybe a plug replacement this weekend also.