STFT1 +14% at idle

[StockBobby]

FE1

Just flashed my tune and my short term fuel trim is reading +14% at idle. Why does my ecu think im running lean? Is this a vacuum leak?

I have installed prl cold air intake, this is the only mod I can think of that I have installed might be causing this.

Thanks in advance for any help gentleman

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[Shankmeyster]

Do a trim relearn by disconnecting the negative terminal on your battery for 30 minutes.

 

[Cueyo]

Holy lean! Did you plug the MAF sensor back in/is it loose?

 

[StockBobby]

So I did just go back to 91 after running an E blend. But the tune was flashed literally right after filling my tank. Does the ECU keep fuel trim after a new flash?

 

[StockBobby]

Holy lean! Did you plug the MAF sensor back in/is it loose?

I installed the CAI months ago and no problems until now.

 

[StockBobby]

update. Couldn't find any vacuum leaks, no loose connections on the intake, pcv appears fine. Am currently sitting around with my battery terminal off to relearn fuel trims. Thanks for the idea @Shankmeyster

 

[Cueyo]

So I did just go back to 91 after running an E blend. But the tune was flashed literally right after filling my tank. Does the ECU keep fuel trim after a new flash?

Fuel trims usually are worse than expected immediately after a reflash. If you reset the engine adaptation (ie: battery terminal or via scanner), it could help. There's also the chance that when running e85, you destroy your catalytic converter. I ran too much e with a pops and bangs tune on my previous civic and that's what it did. It ran itself rich in my case, so I doubt that's your problem.

 

[ctechauto]

Fuel trims usually are worse than expected immediately after a reflash. If you reset the engine adaptation (ie: battery terminal or via scanner), it could help. There's also the chance that when running e85, you destroy your catalytic converter. I ran too much e with a pops and bangs tune on my previous civic and that's what it did. It ran itself rich in my case, so I doubt that's your problem.

Destroying the cat was from your pops and bangs tune, not from E. Ethanol actually lowers EGTs. I know you mentioned yours was from running rich (from the pops and bangs tune), but really talking about the previous sentence.

 

[StockBobby]

EVAP purge valve is leaking. Ordered the part will install tomorrow

 

[StockBobby]

EVAP purge valve is leaking. Ordered the part will install tomorrow

Have replaced the EVAP purge valve and my trims are fluctuating between ~3% and 10%. Is this normal?

 

[pwp25si]

In my non professional opinion, stock trim is very rich, and ive always seen negative ltft before j got a tune.

Have replaced the EVAP purge valve and my trims are fluctuating between ~3% and 10%. Is this normal?

 

[StockBobby]

In my non professional opinion, stock trim is very rich, and ive always seen negative ltft before j got a tune.

Im running an OTS tune right now, so not stock fuel trims. I should be at 5% max im pretty sure. I did replace my purge valve and my trims dropped to 10% from 14% which I think indicates there is still a leak. I found that when I press the brake the fuel trim spikes which is leading me to believe a vacuum leak somewhere in my brake booster.

Still investigating.

 

[pwp25si]

Im on phearable 1.5r and im ltft 0%, k con at .48-.49.

Im running an OTS tune right now, so not stock fuel trims. I should be at 5% max im pretty sure. I did replace my purge valve and my trims dropped to 10% from 14% which I think indicates there is still a leak. I found that when I press the brake the fuel trim spikes which is leading me to believe a vacuum leak somewhere in my brake booster.

Still investigating.

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