When I'm crusin through town sometimes when I let off the gas and start coasting(downhill usually) My car will drop from like 2400 RPMS down to almost idle or 700 to 800 RPMS and then jump back up to about 1500 or 1600 RPMS. It does this everyonce in a while and not when I have been boosting or anything. The only mods I have are K&N FIPK and a Bosch Bypass valve. BTW I have my A/C hardwired to a toggle switch b/c it doesn't work but I have it turned off at nights b/c it is still cool at nights here. Don't know if that has any relevance but I thought I'd mention it. If anyone has any ideas or suggestions I'd like to hear em. Thanks Bill.