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Discussion Starter · #1 ·
So I've been having this code pop up it awhile now and can't seem to figure it out
It's code P0174 system too lean.
I've replaced the fuel pump, fuel filter, cleaned the mass airflow sensor with nothing helping.

I'm goin to replace the PCV valve as well soon but if that doesn't fix it then I'm at a loss. Anyone else have any ideas??
 

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1,132 Posts
Discussion Starter · #4 ·
Have u tried replacing the upstream o2 sensor yet? I have the same code plus one p0171 and p0174 and u can tell im not running lean im running pig rich however i still need a tune and i eliminated the rear o2s so i still have yet to replace my o2 upstream. Just an idea. It could also be a vacuum leak as well so look for that as well
Well I havnt replaced any O2 sensors but I do have a custom tune by Bama to compensate for my O/R pipe and 70mm throttle body and plenum
 
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