When I got my AC recharged at the dealer this summer, one of the techs noticed the lift pump was only cycling for half the time as the other 24valves he had worked on. I noticed this too, when you return smarty back to stock, the lift doesn't even cycle for a second, before the smarty it would cycle for over a second. I said it was the FASS lift pump anyway, so he immediately forgot about it. That is about the only thing that I noticed; otherwise, completely undetectable.