In all honestly this is really the first bad experience I have ever had with Urotuning (Why I still gave 4 stars too) but i will say Spencer did everything he could to get me set up with the right stuff it was moreso intervalves issue with oxidized valves. Spencer had them send me replacements and I was told that it would come off at first start. I really find that hard to beleive though being that 1st Intervalves replaced them and 2nd I took a dremel with a souring wheel on it and it took some off but not all the only reason i didnt say anything is after lapping them I cant see where it would hurt. Wish the TRW valves i order origianlly were in stock but time will tell on these.