Aftermarket BOV's have the same thing on the supra as the MR2 suffer. Blow off, rich, and we have a habit of stalling out from time to time when coming to a stop under those conditions. Some piggy back fuel computers say they compensate, but not for our more sophisticated Karman-Vortech setup. One needs to completely replace the ECU to get around it entirely, or a MAP sensor based conversion like the older and discontinued HKS VPC.
Bob