Josh, Until the 02 sensor heats up from the exhaust and starts sending a voltage to the ECU, the car is running on a fixed air to fuel mixture ratio. Then when the 02 sensor / engine heats up to it's normal operating temp. is the time to adjust the mixture screw to correct the seeking. The air to fuel mixture is either rich or to lean and the adjustment needs to be done to bring it back into sink. I would suggest you do this after you have installed a new 02 sensor and adjust this is when the car is hot. If any questions your welcome to call 12/7. John Hervey www.specialtauto.com -----Original Message----- From: stainlessilusion [mailto:5n-@xxxxxxx] Sent: Sunday, March 13, 2005 3:12 PM To: dmcnews@xxxxxxxxxxxxxxx Subject: [DML] The FV Guys I just had a quick question about the frequency valve if anyone can help me out. My engine idles fine when I hear the FV running, it is the distinct sound you can tell its running. Then it suddenly cycles off and my engine idles a bit worse and starts to idle up and down for a little while until the FV starts back up again. Problems with the wiring or is this normal? Thanks for past and future help!! -----Dani B. #5003 To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/