In the us, lexus initially issued a tsb to just do a top engine cleaning to cars exhibiting symptoms of buildup. The problem is the carbon was returning. So they changed the tsb and now if u have the symptoms they do the cleaning and replace the pistons and seals in order to prevent buildup from reoccurring. Many have said even this is not a complete fix as it just slows down the buildup and cleaning may be required at some point. Not all cars get the buildup, but it seems most do From what I've read there are 2 ways to address it. Either install a catch can (search threads) to prevent it, or wait to see if it occurs and do cleanings as required. Either way its not that expensive and I wouldn't let u hold u back on modifications
Last edited by tomiv9; 07-26-14 at 07:55 AM.