first off, i am new here and any help is greatly needed. i have 02 druramax with 198,000 miles just put a set of injectors in that came from a friend that bought them new and his motor blew a head gasket. the injectors has less than 10,000 miles, worked great in his motor. mine was blowing smoke at idle and everyone told me it was injectors. changed them and now no smoke but turns over a while when tring to start. did find a pin hole in fuel line and fixed that. even went back threw and checked the o-rings on driver side and found one messed up so we replaced that. now here is another problem, while driving it yesterday(just got it back together) i noticed a knocking noise only around 1,900-2,000 rpm. when i parked it it didn't have any deisel in the oil, before i changed the injectors. when i first did the swap i did drive it about 6 miles and parked it until we just went back threw it and found that bad o-ring. it did have some deisel in oil this time. sounds good at idle and even just reving it up up it sounds good, but going down the road yesterday it sounded horrible. its like it only does it under a load. it does has a older banks 6 gun programmer on it, gonna try to unplug that tomorrow. it almost sounds like it is detnating(not sure on spelling). any ideas? could there be something wrong with the computer thing under the hood that the fuel goes threw? thanks for any help.