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Discussion Starter · #1 ·
Guys I need your help.
Recently I noticed that at WOT air-fuel ratio shows me 20:1, but at idle it holds between 14.0-14.6, at 2k-4k somewhere between 12.9-13.6. But when I push the pedal down to the floor I see 20 and even when I release pedal it hold 2-3 seconds and drops down to the normal 12.9-13.6.
There is no power loss at WOT, pony runs great, no engine overheating. Pony is almost not modified (Roush intake, 3.73 axle ratio).
What can cause this numbers? Probably somebody had the same issue?

Vasiliy

P.S. Just forgot to mention - 2013 V6, 3150 miles.
 

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When you take your foot off the pedal it goes into a high vacuum situation and the afr will go very high and that is no problem. If it is going that high at wide open throttle under load then you have an issue, maybe a leak in your CAI.

You say you see high afr when you push the pedal down, is this when just sitting or when you are running down the road?

Also, what AFR gauge setup are you running? Using the OEM O2 sensor or have you added an aftermarket one?
 

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You're using the little dash app right? Sampling rate is VERY low on the factory setup. You need to datalog properly using an external device to really see what's going on.

The car would not run at 20:1, especially high load. It'd be backfiring, spitting monster as it struggled to ignite a mixture that light. It's clearly bad data.
 

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Discussion Starter · #4 ·
You say you see high afr when you push the pedal down, is this when just sitting or when you are running down the road?

Also, what AFR gauge setup are you running? Using the OEM O2 sensor or have you added an aftermarket one?
I'm running OEM O2 sensor, as far as I understand it is narrowband and may show not real data. This issue appears both when I'm running or sitting.

You're using the little dash app right?...
...It's clearly bad data.
For sure I need to log all the data with SCT. Will see, probably it is just an issue of cheap sensor :)
Guys, thank you for your input, it really helpful.
 

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OEM sensors are wide band, definitely not cheap.

And I didn't know you were using the dash app for this.

Get a real gauge, probably a very different outcome.
 

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I'd datalog with the SCT Livewire Gen 2 software.

The gauge may be slow but I've yet to see one tuner prefer a tailpipe wideband or further up placement to the factory, well placed, wideband O2 sensors. If sample rate sucks, datalog less than 20 items at once until it clears up.

Does your fuel have any ethanol content? Is it leaded fuel by chance? Basically, fuel information is needed.
 
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