I'm sure its been beaten to death, but.. when i bought mye 2002 firehawk it had allready installed a ported an polished TB, a descreened SLP mat, a smooth bellows slp, and an slp lid.. I'mSince SLP puts a resistor in the maf, making it run leaner, does this also effect closed loop ? put another way, will this affect fuel economy . I get 35-36 mpg with my M6 , and stock 3.42 gears.