Well I have to agree, It might be ok now and again, but yes my exaust tip was full of a yellow powder residue. I'm sure that would be through the whole system,eg, turbo, bov, hot/cold pipe, I-cooler, waste gate/ actators and maybe even turbo lube oil/ filter. It was a very dry dusty and grity kind of residue. It worked ok but now I think I'll de tune to soft edit to run 95Ron in future.