Idle rpm fluctuation with oft stage2+ e85 tune(ac off)
 

I have 2013 Scion FR-S. Today I noticed that when I am idling at a light, the rpms go to about 800 then slowly drops to 630 ish over a few seconds. Then there is a slight shudder and a clicking sound and the rpm jumps to about 800 again. The process then repeats. The A/C is off. I’m not sure if this was always there and if I just start noticing it.

Digging thru some related threads seems 2013 does have idle fluctuation issues. But I thought that was supposed to be fixed with the oft tune? I am on E85 stage 2+ oft tune. Is it normal to still have this issue with the OFT tune?

check fuel trims not over 19% check manifold vaccuum about 4 psi at idle if your ift that will ve about -10 on boist paraneter as its reluative to atmospheric ie 14 psi