I was having misfires when Cobb was on. Walnut blasting and replaced plugs at the same time fixed it. Don't know/care which part fixed it it runs much, much better now.
'09 525xi | Comfort Access, Moonroof, Softclose, PDC, CIC upgraded
'07 335i E90 (sold) // '03 Porsche Boxster (sold) // '07 Alfa Romeo GT 2.0 (sold) // '06 325i E90 (stolen) // '99 Alfa Romeo 156 (sold)