It has 600 miles since I got my 05 CTD Ram 2500 (95000 miles) back from the dealer who replace #1 cylinder fuel injector (under warranty) and wiring harness for fuel injectors, my mpg has dropped by 3 mpg and the truck is sluggish on acceleration. Any ideas what causing this problem? I am going to the dealer this week. No codes are showing up. Do they reprogram the fuel system after replacing injectors?

 

When you rev your truck up in park or neutral does does it idle down properly? If it doesn't you need to replace all six. When you take it back to get it checked make sure they do a rail pressure test(make them give you a copy of the results) and from experience when one goes they all go.