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Flex fuel tune check engine

stangs650 702

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I’m on a flex fuel tune recently I been getting code p0174 and p0171 system lean but my afr is reading 12-13
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ChitownStang

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I’m on a flex fuel tune recently I been getting code p0174 and p0171 system lean but my afr is reading 12-13
Did this happen right after a fill up? Whose flex tune do you have?
 

kinelisch

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happened to me when I went E40. Im back at 93 for that reason...
 

Alan Applegate

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My first question would be... Are you sure it was E40?

From Google: To measure the ethanol percentage in gasoline, mix a known volume of gasoline with an equal volume of water in a graduated cylinder, shake it, and let it settle. The amount of liquid that separates below the original water level indicates the ethanol content; subtract the initial water volume from the final measurement to calculate the ethanol percentage.
 


ChitownStang

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A proper flex tune lets you run anything in between 91 - e85. After you fill the tank it may take 10 miles or so to adjust air fuel ratios so you should drive nice during this time. You should not be running you e85 tune with anything less than e70. This can cause serious problems.
Who’s the tune from?
 
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stangs650 702

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happened to me when I went E40. Im back at 93 for that reason...
A proper flex tune lets you run anything in between 91 - e85. After you fill the tank it may take 10 miles or so to adjust air fuel ratios so you should drive nice during this time. You should not be running you e85 tune with anything less than e70. This can cause serious problems.
Who’s the tune from?
A Cali tuner but it weirds at first it didn’t happen then I went to93 gas and that’s where I had issues with that and now I just stay on 85
 

ZXMustang

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This is why its rare anyone does these anymore. User issues 9/10 times. No offense OP, not even worth doing these.
 

ChitownStang

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This is why its rare anyone does these anymore. User issues 9/10 times. No offense OP, not even worth doing these.
This guy is the first one I’ve heard of having an issue and he used some local shop in Cali.
I had 2 different flex tunes on my Mach 1 with 0 issues
 

ZXMustang

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This guy is the first one I’ve heard of having an issue and he used some local shop in Cali.
I had 2 different flex tunes on my Mach 1 with 0 issues
Being on my end, all I’ve heard of was problems and this is going back to 2018.
 

ChitownStang

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Being on my end, all I’ve heard of was problems and this is going back to 2018.
You would obviously see more than me but it seems to be operator error in some cases.
I really want to tune my DH but I don’t think you guys have it figured out fully yet tbh.
 

ZXMustang

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You would obviously see more than me but it seems to be operator error in some cases.
I really want to tune my DH but I don’t think you guys have it figured out fully yet tbh.
?

you mean flex fueling? No we aren’t planning on ever doing a flex tune. But I’ve personally tuned several DHs. lol they are virtually the same as GTs with a bit less stock tq management. Hate to break it to you but a tuned GT vs a tuned DH is 1:1. There is no advantage to the DH once all the tq management is removed from the equation.
 

ChitownStang

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?

you mean flex fueling? No we aren’t planning on ever doing a flex tune. But I’ve personally tuned several DHs. lol they are virtually the same as GTs with a bit less stock tq management. Hate to break it to you but a tuned GT vs a tuned DH is 1:1. There is no advantage to the DH once all the tq management is removed from the equation.
Yes, I mean flex fueling and when I say you guys I mean tuners in general .
It was rushed to market.
So you’re saying a tuned DH makes same power as tuned GT?
 

ZXMustang

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Yes, I mean flex fueling and when I say you guys I mean tuners in general .
It was rushed to market.
So you’re saying a tuned DH makes same power as tuned GT?
Yes. There isn’t a tune difference once you tune out what ford tricked you into thinking was a difference. Stock to stock, the tune files are almost identical with the exception of a bit less tq management for the DH. That’s your extra power. Once removed, the GT makes the same power. Don’t let anyone fool you - more so than Ford did. Ingenious really to dampen the GT a bit further and less on the DH. Saves a lot of cost that’s for sure.
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