What's the most surefire way to dial it in. I read the other thread but there are so many answers. I know the copperhead pcm is special but I've dialed in an old 06 gto using a wideband and used that as the correction factor. Same for an 02 lightning. Both done in open loop. I've compared the tune from a tuner that I pulled from my pcm to a stock file and the maf calibration was the same. I would like to get it down to within a +/-2%