My Duramax LB7 has been smoking white smoke at idle, constant flow every time I stop the truck. You can almost feel the Idle not being very smooth on the truck as if the Fuel Pressure Regulator was not working properly. Now a few weeks ago I had thrown the FPR Code p0089 (while it was smoking at idle). So I began to look into the issue, got a lot of feedback off the forum here. heres what Ive done.

-Checked and replaced Air Filter so thats brand new
-Put a brand new Oil filter and oil change
-Put a brand new Fuel Filter in
-Continuously checking the oil for any sign of diesel within it. None, no smell, or sign of it when checking the dipstick after letting the truck rest.
-Paid very close attention to temperature of truck while driving 200 mile trips and all. Never even broke 200 degrees. Obviously looking for any signs of a bad head gasket.

Then I Looked up some diesel shops or mechanics to get my injectors tested and had my truck hooked up to a computer. Went with Ben from BT Diesel Works, out in Old Saybrook, CT as recommended by a bunch of guys on this forum. He hooked up to computer and found injectors looked good and was convinced it was the Fuel Pressure Regulator, because when at Idle, the idle levels would not stay consistent and ran super high and it showed a spike in the chart on his computer. Plus the combination of that and the Check Engine code pointed to the FPR. so i went ahead and changed it and put a brand new Bosch FPR in.

Started it up, still smokes at idle same amount and same rough idle as if its not staying at a constant level.

What do I do now. where do i go. thoughts suggestions. i need to solve this, obviously without hurting the truck while driving it on a day to day basis?

Also after I changed the FPR was there something I was supposed to reset on the computer or any other tricks to that process other then simply replacing the part?