I have a 98 C230 and stood on my head trying to clear a P0170. Cleaning the AMM just prolonged the time it would take for the CEL to come on. I too, changed everthing, sprayed everything, and finally bought the damn thing. Best $300 I ever spent. More power, better gas mileage, smoother trans shifting, yes the AMM affects the transmission too. Buy it, you probably won't regret it.