I have no other signs really of a bad injector except that the Predator tells me that one of them is between +6 to +8 when idling in Neutral. All others are between -1 and -2.5. Should I remove mods and head to the dealer? And what should my back story be as I don't really have any other symptoms...no white smoke, stumbling or anything like that. Even checked the oil and nothing more than the normal soot. 15,000 miles as of today.

Just tell them that you hear an audible knock at times, and that a friend of yours had a similar problem and it was a bad injector.

I agree. I have one that is knocking consistently now, but in the past it was only now and then. Dang thing is, I can never catch it out on balance rate. :mad:

So, knock is variable enough that your story won't sound like hooey.

I bet you can see signs... Stand behind it while it idles and see if it starts smoking enough to hurt your eyes. It's not always visible when driving or even walking around but if you are near the tailpipe you may notice. Also look when it's dark out and walk around it with a flashlight or another truck behind you.
Mine was doing worse than that, 3 injectors with high rates, and noticable smoke at idle, and stumbling at idle. I told them about those problems and they wanted to wait for codes. Finally I told them I had to have them at least do the reflashes and see if that helped. So 4 days later after they got my new ecm in and reflashed it (tech 2 evidently was not playing nice that day) I got my truck back. Seems to still smoke a bit but not as much. Doesn't stumble at idle though.

Just out of curiosity have you tried running any injector cleaner (like Stanadyne, or the Primrose if you're still runnin B99) through your rig to see if that corrects the problem? I know it sounds like a dealer answer, but I've seen numerous Diesels with “sticky” injectors fixed after injector cleaner was run through them.

I just ran a tank of Stanadyne and I am going to up the % of that on this next tank. Haven't checked the rates again but I will soon. I would be willing to assume that it may be the bio since it has killed a couple of filters for me in the past. As soon as I get the time I will get all my mods off and head into dealer and see if they will even check it out. I also haven't run any bio for the almost the whole summer as supplier has been out of it.

Took truck to dealer and had them take a look at the truck. They replaced injector #8 and got it all done in one day. WHEW! They were really good about it and said it was just stuck. Anyway I will check balance rates when I get it home and see if it's ok now.

Dealer fixed it!!!! What a great experience after hearing all the horror stories on the forum. Balance rates are now all in check!