[04heavychevy]

I bought a 04 gmc 2500hd with 158k on it (lb7) I noticed after driving it for a couple of days it blows white smoke after warm when its idling. Did some research and found it to probably be injectors from others opinions. Took the truck to the stealership today and they said The injectors are in spec that the worst was a +2 and they have to be a +4 to be out of spec. I don't really know what that means but anyways. He said the scanned the vehicle for codes and found a p1621 control module long term memory performace code set. He told me it needs a new ecm (1300 dollars) and this may or may not fix the smoke problem but it needs done before he can further diagnose the smoking problem. He also said it is not possible to put a used one in that it would have to be new. Which i know is not true. Does anyone have any input Please

 

[meeker]

bump... someone will have some help!

 

[daddysLBZ]

Where did you get the truck?Did you know of the condition beforehand?


I am dying to know how the truck needs a ECM and possibly injectors?White smoke ain't good...

 

[04heavychevy]

i bought the truck private party. I did not know about the issues before had. I called a local dealer to double check the warranty on the injectors and they told me he had it in there a month before because of the smoking issue but they would not replace them because they were in spec. I took it to a diffrent dealer.