Surging Idle

[KF4R2011]

Hey guys, just wanted to share a neat thing I found and seemed to be able to fix over the weekend. Basically the issue was that the truck would run fine and then there would be a surge and then idle rough then run smooth, and repeat repeat repeat. Well, I use OBD fusion and happened upon the "deposit loss flow" PID. I graphed it alongside the RPMs and you can see what was happening. Turns out that apparently, the truck does its best to compensate but essentially is left with "blipping" the throttle to correct the AFR when the throttle body seal is out of range. Notice that after cleaning the throttleplate and housing, the liters/sec (L/s) went from 2-2.5 to less than 1. Its also more "active" rather than being on a slow decline, then a correction. I had to drive it around for the re-learn but it seems to be running very well now. I also replaced the PCV valve. Hope this helps someone else... $10 fix maybe with the throttle cleaner and such. I found the The loss flow description on a venza website.