p0171 bank 1 lean and p0174 bank 2 lean
 

i have been running with the same mods for about a year not and never had a lean come up, but now all of a sudden (recently added typhoon intake mani) i am getting these popping up , also on wide open throttle it will cut out

i know basics, check for vacuum hoses leaking, mass air sensor dirty, (i changed the fuel filter less than 1000 miles ago and only run 93 octane gas from shell)

i am gonna do a fuel pressure test,

what type of fuel pressure should be hitting the fuel rails?

RE: p0171 bank 1 lean and p0174 bank 2 lean
 

did u check for leaks on the intake?(with some starting flulid or something)

RE: p0171 bank 1 lean and p0174 bank 2 lean
 

with a bigger intake you suck more air and your mass air meter pings...witch sets of those codes...when i put on my p51 it did the same thing

RE: p0171 bank 1 lean and p0174 bank 2 lean
 

i think it is a vacuum leak, i realized a few weeks ago the blend door for the vent defrost and heater wasnt working right, and i just figured out thats controlled by vacuum! ! it could be a leak in the dash i guess!

RE: p0171 bank 1 lean and p0174 bank 2 lean
 

i have a silmar problem i need help with. i just cleaned my air filter and put it back on. now i have the trouble code bank 2 o2 sensor out. after that i got a code p1157 saying my car is running lean. i checked for vaccume leakes on the intake and when i rev the motor i can hear it sucking but it has always done it. i added slp loudmouth x pipe with cats and a cat back system about a month ago. i put it on so i know the o2 sensors were good. the car has bbk cold air intake,70mm throttle body,upper intake elbow, underdrive pulleys, and a diablosport tuner for power adders. any help would be great.

RE: p0171 bank 1 lean and p0174 bank 2 lean
 

FIXED

i hate those hard plastic lines, there was a crack in one off the intake, probloy broke it while i was swapping intakes

it was actually the line from the intake to the vent thingy for the def, vent, heater no mo code and ac is cold as hell again ! !