just installed a set of ta performance stock replacement headers and all can say is WOW!! sound and look awesome. the fit was right on spec. spool up is greatly noticable! the only problem i have is now my car is idleing at 840 to 860 o2's my blm's are at 132. my fuel pressure is 42 line off. cant really change anything without sacrificing wot fuel. can my ait filter need cleaned and or changed or my maf changed to ls1 or also this one cleaned my a/f is 13.8 at idle