High LTFT's and Hesitations

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11 MS3 Sport
I've recently installed a Cobb SRI and i've noticed immediately that I have wildly higher LTFT's in comparison to where my MSCAI was at perfect 0.0's almost all the time. My Cobb SRI puts me at +16 idle and +8 WOT.

After searching, it seems that this is normal. So, I won't even stress much about the LTFT's.

However, ever since I installed it, light throttle cruising or decel is sorta awkward as the car will almost seem to close the throttle plate abruptly, causing the engine to buck lightly, or the car will feel like the brakes are being lightly applied. Basically, it's hard to maintain constant forward motion as the engine will fluctuate. RPMS don't drop, Fuel pres doesn't drop, LTFT's don't change when this happens.

I had to install my stock airbox, and it went away for the most part, but still happens. Any ideas? Maybe a light misfire? Could it be the MAF? Plugs? Car is brand new, shouldn't need plugs really.
 
Car is stock, stock tune, stock internal fuel pump. I just notice the boost/vacuum change everytime the car hesitates. It'll fluctuate between -9 and -11 rapidly during the hesitations.
 
You shouldn't be allowed to contribute to this thread if you're "modded" and don't know what that is...

Don't be such an pompous ass, not everyone is much of an "educated" tuner as you, if the guy asks, is it really that hard to type the extra words to help a fellow MS3 owner out? I don't know about you guys but I remember when I first started tuning my 01' Impreza RS and didn't know wtf anyone was saying half time on the forums, you have to start somewhere
LTFT= Long Term Fuel Trim
 
Don't be such an pompous ass, not everyone is much of an "educated" tuner as you, if the guy asks, is it really that hard to type the extra words to help a fellow MS3 owner out? I don't know about you guys but I remember when I first started tuning my 01' Impreza RS and didn't know wtf anyone was saying half time on the forums, you have to start somewhere
LTFT= Long Term Fuel Trim

All i'm looking for is answers. I've done all the research I can and now i'm left with nothing. The answer i'm looking for, may be within other experienced "Modded" owners.

I find it quite odd that he's "modded" but doesn't know what that means. So basically, that means he has an intake, maybe exhaust, but no means of monitoring if any of that is helping or hurting his car.

Thanks for the manners lesson. Now, do you have an answer or being forum police?
 
Just being the devil's advocate saying perhaps he has a way of monitoring but doesn't know the acronym? I apologize for any offense I may have made, glad to see you didn't take it personally. But I can see your point, sorry I don't have a solid answer either for you, that is pretty odd that none of that changes yet it acts as if it's shutting down? Maybe your coilpacks could be faulting?
 
You sure you didn't damage the MAF when changing to the SRI? LTFT's should be single digit and not double. Did you unplug the battery and press the brake for a bit after to fully discharge the system so it can relearn the trims? How long did you drive with the SRI before pulling it out? It takes a bit of time for your trims to settle. Something along the lines of 10 restarts and about 50 miles I would think. You should not get on the car until this settles.

Also, check all your clamps to ensure they are all tight (there are 5 of them). The turbo inlet being the one that is usually really lose. Maybe in changing the SRi you pulled it out a bit.

Those are some of the things I would check/do.
 
you could have unwanted air entering any of the vac lines if your clamps are loose. that would throw your fuel trims off from what they should be and cause your car to hesititate. any unknown air would cause a hesitation on the intake side. check the usual suspect....the turbo inlet pipe. that could cause your problem.
 
I pretty much checked everything about 3 times so far. Everything seems ok. Car is still hesitating even with stock air box. I really frickin wish this thing would throw a CEL so we could get to the bottom of this LOL!!!

BTW, car sucks major balls with the stock airbox. But i'm at 0.0 LTFT's heh, that sucks.

BLH it's all good - just trying to get to the bottom of this and running out of options. Everything is clamped down tight, fuel pressures are good, afr's are good, everything is good. But it literally hiccups out of nowhere and I wish I could figure it out.
 

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