Battling this right now. Pump replaced, PCV replaced, heads were just removed and sand-blasted. WHen put back together my gas mileage went up to 22 street. Emissions code is back, rough idle and a little loss of power, average MPH back to 17.8... The codes stayed off long enough to smog check my car. Im so tired of this 745 right now.
A second Indy shop says that even though the (warranty shop) removed and sandblasted the heads they didnt do it right and that is why the problem is still there. My Indy Shop (specialize in BMW) wants $2000 to fix it right. My warranty shop is a bunch of Jack-Holes that screwed other things up on my car and didnt fix this problem right... Those 645's are starting to look better and better...
IF possible, I am interested in disabling my secondary, why the $500 to do it?