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High AF Learning 1 at idle Cobb OTS Stage 1

8141 Views 3 Replies 3 Participants Last post by  slumber12
Wondering if anyone could give me some advice. My 2007 FXT is bone stock with a Cobb OTS stage 1 map. I just uploaded the map the other day and noticed that at idle my af Learning 1 value goes up to +14.8 and hovers there until I apply throttle. As soon as apply throttle it levels out at 0 but as soon as i left off the gas and the rpm's drop below 2k it shoots back up into the 14's. Would this imply i have a vacuum leak somewhere or could it possibly be cobbs ots map. I checked the air intake, turbo inlet pipe, and vacuum lines for leaks and didn't notice anything. Other than that the car is running fine except i do get a slight shutter while idling but feedback knock looks good and so does the DAM. Any advice you could give would be awesome. Thanks
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Sounds like a vacuum leak to me, if you're worried it's tune related you could flash back to stock and still monitor A/F learning #1 - but I'd bet money on a vacuum leak.
Once you rev it, you are crossing into later (B, C, D) learning values. Idle is focused around learning trim A, generally speaking.

If you are stock and seeing it head THAT positive, its safe to assume there is a Vac leak somewhere post-MAF, as mentioned by @MaTTyBiGs .

If it isnt as obvious as a hole somewhere or a popped of hose, youll have to have a shop perform a simple pressure or smoke test to determine what is leaking.
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Thanks for the advice and I agree, it has to be a vacuum leak somewhere. I may have to take it over to P&L to see if they can give her the old smoke test.
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