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COBB AP numbers after a 200 mile drive...


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Am I the only one who thinks that boost is too high for stage 1?

 

No, you are correct, but no point in dwelling on it since the basics haven't been done yet. OP still hasn't posted fuel learning, let alone test for leaks that might be indicated by said values.

 

If an early boost leak (such as the end tank you suggested) prevents an accurate boost control reference, that will naturally impair wastegate operation.

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Am I the only one who thinks that boost is too high for stage 1? Stock turbo? Confirmed? Stock downpipe?

 

Stock turbo and downpipe. Is the turbo working overtime to make up for the extra air leaking in? No idea.

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No, you are correct, but no point in dwelling on it since the basics haven't been done yet. OP still hasn't posted fuel learning, let alone test for leaks that might be indicated by said values.

 

If an early boost leak (such as the end tank you suggested) prevents an accurate boost control reference, that will naturally impair wastegate operation.

 

 

 

Ah... gotcha

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Is “fuel learning” labeled something else in the AP? I don’t see it listed.

 

In the non-Subaru world, it's long-term fuel trim (LTFT). In BtSsm world, fuel learning. In Cobb world, A/F learning.

 

The gauges of interest here are

A/F Learning #1 Range A

A/F Learning #1 Range B

A/F Learning #1 Range C

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I am picking up the smoke machine tomorrow AM. It hooks to a compressor and is Smoke Pro model so pressures can be dialed in to not mess things up.

 

Nice. Wish I could justify buying one of those, but my paint can works like a charm.

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I'm borrowing the smoke machine. That's how cool Thompsons Import Specialties is here in Bend. He asked me to take good care of it, which I will.

 

 

 

Here are the fueling numbers 2d33c61cc1d37ac82c647d17426d2c2f.jpg

 

 

Sent from my iPhone using Tapatalk

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I'm borrowing the smoke machine. That's how cool Thompsons Import Specialties is here in Bend. He asked me to take good care of it, which I will.

 

That's extremely cool of them, I am interested to hear the results.

 

You might consider data logging your next test drive, it could potentially reveal some more information than just the AF learning by itself. Although your smoke test will probably reveal a lot as well!

 

Also, might be worthwhile to contact Cobb, they're customer support has been exceedingly helpful in similar situations for me in the past.

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The off-the-chart value in range C suggests a fuel problem rather than a vacuum leak. I would do the following:

1. Display the roughness 1-4 monitors on the AP, and with the car parked, hold the throttle at various RPM levels and see if any numbers > 1 appear on any of those monitors.

2. If the roughness (misfires) are zero, get your hands on a fuel pressure gauge (not Harbor Freight, that thing is crap) and tee into the line just after the FPR. Check pressure against spec at idle vacuum and with no vacuum applied. See here for full details:

http://www.bedug.com/pics/Subaru/2007.zip

H4DOTC document p. 136, I believe.

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The off-the-chart value in range C suggests a fuel problem rather than a vacuum leak. I would do the following:

1. Display the roughness 1-4 monitors on the AP, and with the car parked, hold the throttle at various RPM levels and see if any numbers > 1 appear on any of those monitors.

2. If the roughness (misfires) are zero, get your hands on a fuel pressure gauge (not Harbor Freight, that thing is crap) and tee into the line just after the FPR. Check pressure against spec at idle vacuum and with no vacuum applied. See here for full details:

http://www.bedug.com/pics/Subaru/2007.zip

H4DOTC document p. 136, I believe.

 

Perhaps an injector problem?

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The off-the-chart value in range C suggests a fuel problem rather than a vacuum leak. I would do the following:

1. Display the roughness 1-4 monitors on the AP, and with the car parked, hold the throttle at various RPM levels and see if any numbers > 1 appear on any of those monitors.

2. If the roughness (misfires) are zero, get your hands on a fuel pressure gauge (not Harbor Freight, that thing is crap) and tee into the line just after the FPR. Check pressure against spec at idle vacuum and with no vacuum applied. See here for full details:

http://www.bedug.com/pics/Subaru/2007.zip

H4DOTC document p. 136, I believe.

 

 

 

So while the engine was warming up I didn’t want to rev it up. While sitting there at 1500rpm this is what I saw. Once it was warmed up it was not throwing any new numbers. I will drive further and see if that changes. 3b0ec752cb2d04d671e3fac61e5d79ed.jpg

 

 

Sent from my iPhone using Tapatalk

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OK, I'd be looking at fuel supply (regulator or pump). Possibly upper O2 sensor or MAF sensor. Have you cleaned your MAF sensor yet?

 

Obviously no harm in going ahead with the smoke test, especially since you are a bit lean in the A range.

 

Edit: looking again at those fuel trims, I suspect the sensors more than the fuel supply. But you can test the fuel pressure; you can eliminate the sensors only by replacing them.

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I will get the MAF cleaned as well. I did install a freshly oiled K&N filter in the airbox, I guess it is possible that some of that oil has fouled the MAF. It was re-oiled correctly but that does not mean much.

 

According to K&N this is not possible. I will clean anyway...

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I am not surprised. I did have the SPT CAI on the car when I bought it. I took that thing off ASAP as it was running lean at that point as well. I swear that some guys just want the noise and don't care about the consequences.

 

I'll post pics of the smoke and MAF later tonight. I still suspect the AOS that I installed is casuing a leak someplace as well. We will find out soon! I hope.

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That was the vacuum line for your fuel pressure regulator... that would hurt....

 

Also, it takes a good while for FLKC to go down. Either reset the ECU or drive for a while in different RPM ranges. Since it's "Learned", it takes a while to "unlearn".

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