E85 check engine light

[hchf1234]

recently wanted to try e85. Requested a flex tune from bama and got my tank as low as 5 miles left filled all the way up with e85. Ran fine for the next 2 days then on the way to work i noticed when i slowed down the car would stutter and then i got a check engine light for p2099 and p2097.

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[ZXMustang]

It didnt have enough time to learn the E completely before the trims matured from the fill up, so the trims are way off (+20 to +30% most likely). You need to reflash down that flex tune again or do a KAM reset to trigger it to learn the ethanol content again. Once the E has gotten all the way through the fuel system, the AFR will start to come down around 10.0 depending on how good the E you got was.

Otherwise its going to run like this until you refill gas again to trigger a relearn. And its a certain amount or more, I forget what it is. Like 10 gallons or something you need to refill before it will trigger the relearn naturally... Someone correct me on that.

So bottom line, just reflash down that flex tune again and then let the car idle for like 10-15 minutes after. It will learn down the AFR and it will run like a beast. You can see the AFR going down on the gauge in the DIC.

 

[K4fxd]

Those are codes for the engine running rich. Would need to see the logs to figure out what is actually going on.

 

[K4fxd]

I forget what it is. Like 10 gallons or something

Factory is set to 10% so 1.6 gallons should trigger a reset.

I tend to agree with your assessment.

 

[ZXMustang]

Factory is set to 10% so 1.6 gallons should trigger a reset.

I tend to agree with your assessment.

Yeah 10% not 10 gallons. I knew it was 10 something...lol

And yes its running rich like +30% trims from burning the E (9.8-10.2 AFR) but the car is trying to command 14.10 AFR... But technically its not "running rich". If the trims are not maxed out, then its running at commanded but also adding a ton of fuel to offset what its seeing vs what it was told it should be seeing. But its not "running rich". Its running at the correct stoich for E just really on the ragged edge with what it can correct for I bet.

 

[ZXMustang]

This is what it looks like in real time when I reflashed my car that was already on full E and it started the learning procedure from E10.

 

[K4fxd]

But its not "running rich". Its running at the correct stoich for E just really on the ragged edge with what it can correct for I bet.

This is why I want to see the logs. I've never let my trims be out so long as to get a code.

 

[ZXMustang]

This is why I want to see the logs. I've never let my trims be out so long as to get a code.

Agreed. But no offense to the OP, I dont think hes going to be able to get a log for us if hes using BAMA. I doubt he has HPT or the SCT equivalent to do logging that could be posted. I may be wrong, but I doubt it.

 

[hchf1234]

Yeah 10% not 10 gallons. I knew it was 10 something...lol

And yes its running rich like +30% trims from burning the E (9.8-10.2 AFR) but the car is trying to command 14.10 AFR... But technically its not "running rich". If the trims are not maxed out, then its running at commanded but also adding a ton of fuel to offset what its seeing vs what it was told it should be seeing. But its not "running rich". Its running at the correct stoich for E just really on the ragged edge with what it can correct for I bet.

i ordered one of those test kits i’m gonna test it when i get it

 

[DougS550]

Do the inline E85 sensor you install inline of the fuel line work? I think they are blue tooth?

 

[K4fxd]

Do the inline E85 sensor you install inline of the fuel line work?

Not currently supported but will be soon. Lund will be the first to get the system.

Lund might already have it.

 

[ZXMustang]

Not currently supported but will be soon. Lund will be the first to get the system.

Lund might already have it.

You saying it will work with the factory ECU and adjust AFR depending on E content? Like the LT1/4 cars do with E sensors?

 

[K4fxd]

You saying it will work with the factory ECU and adjust AFR depending on E content? Like the LT1/4 cars do with E sensors?

Yes

 

[DougS550]

Not currently supported but will be soon. Lund will be the first to get the system.

Lund might already have it.

I don't want to use Lund, but I will install one

 

[ZXMustang]

Yes

That would be something. I would be in for that if thats the case. For real.

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