Last year I had a complete nightmare with the car. The check VSC, loss of power, problems with lexus who tried to charge me a fortune etc etc etc. So I took the bull by the horns and done some research. I stumbled across the use of BG244 annually along with AR6200 with each fill up of diesel Well a year on (with zero problems) the car was in for service and I instructed the mechanic to clean EGR and the exhaust manifold (as instructed by a lexus tecnician). He reported back to me that the EGR had only a little carbon and the manifold didnt even need touched! Now I hope this post doesn't result in sod's law and the car goes on the blink again but I thought I should share this to help others prevent the nightmare scenario. Also since starting these fuel treatments I notice a difference in power, quieter engine though my mpg is still pretty low at approx 32 mpg.