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Okay guys, need some help with this one...

2012, went from AAM catless midpipe/cobb AP to full bolt-ons/ecutek. Car drives great, tune is good as far as Ben can see. But I have a couple of issues.
Here's my mod list:

- Asnu 1100's
- DeatschWerks DW65C pumps
- KP Catless downpipes, http://store.kingspe...olt-on-downpipe
- SBD catted/resonated midpipe
- GotBoost Upper and Lower IC piping
- GotBoost 3" intake
- GFB BOV's
- EcuTEK tuned by Ben Linney

Issues:
- I have what sounds to be a strange whistle/whine under boost that doesn't sound like other bolt-on car I've heard.
- Idle hunting/surging
- two codes - P2096 and P2098. Cleared them twice but they come back

Things we've tried:
- Check for intake leaks
- Tightened the springs on the GFB Bov's, tried both full atm and full recirc
- Idle learn/Bank balancing done by consult and by ecutek several times. successful each time, but yet the hunting comes back
- Check for exhaust leaks

Things about to try:
- putting stock BOV back on
- swapping rear O2 sensor (left side with right side)
- rear O2 sensor spacers/anti fouler

I could swear it sounds like an exhaust leak (turbo spooling up) but the mechanic said he's checked everything for leaks. Any other suggestions?
 

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The whistle noise is likely the mid pipe or maybe a slight a exhaust leak.

I have had a few people complain about the same whistle , to me it sounds pretty normal for a car with aftermarket exhaust that's not super loud.

As for those codes, you'll need them turned off by your tuner.

As for the idle, if your sure you have no leaks then have your tuner spend a little time tweaking the idle.

1. Have tuner turn off those two codes
2. Make idle log when the car is warm and cold for the tuner

Good luck!

John
 

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Discussion Starter · #4 ·
Thanks John, very much appreciate the response. Just out of curiosity, do the Cobb AP tuned cars with catless downpipes also need those two codes turned off?
 

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P2096 is almost always caused by some sort of exhaust leak around the secondary O2 sensors in just about any car that I tune. See if you can find someone to smoke test the exhaust for leaks. I would imagine a whistle would be have to be a small leak in order to produce the needed high pitched tone.
 

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Discussion Starter · #6 ·
Thanks rob! Will confirm.
 

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SBD midpipe to stock catback will almost always leak if you didn't get the adapter flange/gasket...
 

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Ive also seen downpipe to midpipe flange warping which is a more likely spot to trip the codes.
 

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Your idle surge/hunting and catalyst codes might be 2 different problems. Intake manifold has to come off to install injectors. There are many hoses that attach to that upper manifold. Go back with a light and triple check that you hooked everything back up.
 

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Discussion Starter · #10 ·
Ive also seen downpipe to midpipe flange warping which is a more likely spot to trip the codes.
Thanks again Doug. Will do some smoke testing as rob suggested.
 

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Discussion Starter · #11 ·
Your idle surge/hunting and catalyst codes might be 2 different problems. Intake manifold has to come off to install injectors. There are many hoses that attach to that upper manifold. Go back with a light and triple check that you hooked everything back up.
Yep agreed. I think idle may be the bov
 

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Discussion Starter · #12 ·
Your idle surge/hunting and catalyst codes might be 2 different problems. Intake manifold has to come off to install injectors. There are many hoses that attach to that upper manifold. Go back with a light and triple check that you hooked everything back up.
Will recheck. Question though - vacuum pressure at both throttle bodies are the same. Wouldn't a leak show up as a discrepancy between the two?
 

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Depends on the severity of the leak. Generally you will see a difference if fuel correction 1st. It has to be a pretty bad leak like a hose simply not connected to upset vacuum readings.
If something was hanging lose it would be a very bad correction swing 90's to 120's and back.
 

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Discussion Starter · #14 ·
Depends on the severity of the leak. Generally you will see a difference if fuel correction 1st. It has to be a pretty bad leak like a hose simply not connected to upset vacuum readings.
If something was hanging lose it would be a very bad correction swing 90's to 120's and back.
thanks - so I can say with certainty that short term fuel trims at idle when it's hunting IS DEFINITELY swinging back and forth from 100 - 125 and back down to 100
 

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Why do these codes need to be switched off?

Im running nearly the same setup on my GTR with them codes active, dont get these dtcs....so switching them of is one way to solve the problem...dont think its the right way.

Tuned on ecutek and running awesome....

GFB blowoff should not give any problem too
 

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I would check the flange on the GFB BOV. I've removed multiple sets of of GTR's with warped flanges. A leak at the BOV will cause what you are experiencing. Throw the stock BOV's on and see if it fixes it. Set the OV on a flat surface bet it wobbles a bit. Not a fan of the GFB BOV's here.
 

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most of the time that I see hunting idle with no mechanical issue it's due to inconsistencies between adjacent cells in the timing/cam advance/VE/fuel tables... it's important that these tables be smooth and the same if the load at idle crosses between two or more cells...

since this car is on a maf tune, VE doesn't apply... but it's easy to overlook an errant cell...

when you look at short term fuel trims on each bank... are both banks hunting or only one?
 
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