I know that lots of folks have check engine light problems and I've had them before. So here is my latest--I am repeatedly getting three codes--622, 1689 and 1693. Usually the engine will hesitate slightly--like no acceleration-for a second before the CE comes on. Sometimes I can go 300 miles before it happens and sometimes it will repeat in 20 miles. I had it in the shop and right now they are saying it is a communications problem but they want more time to diagnose the problem. Trouble is we are leaving on a trip shortly and I need to have confidence my 1998 24-valve 3/4 ton dodge won't die on me. Any thoughts on what I should be looking for? Thanks.