I have an 06 LBZ that now has 71000 miles. I recently started running vegetable oil with a separate tank in the bed that has coolant lines and separate heaters. I ran it for about 1000-1500 miles with no issues. But when I drove from ny to texas strait through, my fuel pressure regulator went just outside of Dallas, the injector balance rates are within spec. I ended up limping it to Austin, on the way, it kicked out the code for high fuel temp, which is when I brought up the reading on my programmer, which was reading 240 degrees, so i switched it back to diesel and the temp dropped back to 140 degrees. after replacing the fpr, the truck ran normal and the injector balance rates were all well within spec. On the return trip while on vegetable oil, I had a sensor failure code, when i checked the balance rates there were 3 injectors that were reading really high, between +8 and +12. We stayed the night their. The next morning, after clearing the codes, it only gave another code saying misfire in cylinder 8, so I put some lucas injector cleaner through it and it seemed to clear up, the balance rates were back within spec. Now there is one injector that is reading about +3 to +4, but when i switch back to vegetable oil the balance rates seem to jump all over, and start to run a little rough at idle, after awhile on diesel the balance rates go back to close to 0, but one injector stays close to +4, but it changes to a different injector every so often. I was just wondering if anyone has any ideas on what could be causing the changing balance rates or what can be done to prevent it.