I know that many have had this issue of pulling the powertrain system too lean (bank 1) before maybe my story is a little different.
First of all here are my current mods.
1.9 modded rockers, LS7 lifters
Ac delco iridium 41-104 plugs,new wires
SD Headers, no cat, stock exhaust , second 02 sensor delete from dhp tune. Never throws an o2 code.
zzp Lim, ported gen 3, Full size intercooler (2.5 inches) frozenboost Fmhe, Stock throttle body, hai
zzp modded fuel rail, 60 lb injectors with new o rings, No leaks
zzp mps, 3.4 pulley
Okay so im new to understanding the torque app but ive been getting better. What i am concerned with is that i have i have higher than normal fuel trims at idle
Here are my numbers
LTFT1- Highest value 16.4, Lowest value 2.3
STFT1- Highest value 20.3, Lowest value -5.5
My o2 1x1 highest value is .9
Knock retard is ZERO though
I have only driven the car for about 15-20 miles and the highest ive taken it to is 50ish mph But i did get close to 12 pounds of boost. I know that running fuel trims that high means im running lean at idle and the computer is having to throw at least 20 percent more fuel to compensate for something but i also know that when im driving the numbers go down and seem safe. The tune is off of a buddy with a similar setup that he had 42 lb injectors for and threw it on my car to get me going but i think he added 30 percent more fuel or something like that.
I know that everyone is going to say you have a vacuum leak but i have tried for quite some time to find one. All my lines are connected. No cracks. I sprayed brake cleaner with it running and i didnt hear the engine speed up or anything. I made sure when i put the supercharger onto the intercooler i used a felpro upper plenum gasket as my diagram and put rtv exactly where you are supposed to and torqued it within 20 mins.
My question is , does a p0171 code ALWAYS mean vacuum leak or could it be something else stupid like a fuel injector not being seated properly or bad o ring or harness or something like that? Would getting a proper tune get rid of the problem or is it for sure a vacuum leak?