P0171 system too lean(bank 1)
 

hey lookin for some help with this problem, I was told replacing the front lambda sensor would cure this but it hasn't, I bought a brand new dendo sensor, other things I have done is replace and clean the maf, the problems I have is the car is hesitant on pull and the boost is rough, and dosent reach full boost, any help appreciated thanks

Hi, i had this code recently on my newly brought '53' blob eye sti. The previous owner had fitted an cheapo atmospheric dump valve. As soon as i reverted it back to a standard recirculating valve the code hasnt come back.
May not be of help, but if you have an atmospheric valve fitted, might be worth getting rid of.
Cheers

That is a very common fault code and could be lots of things.

A good read on it here.

http://forums.nasioc.com/forums/show...=475620&page=3


Had the same code on my bugeye sti and it went away shortly after i changed the spark plugs.

A couple of the old plugs were not screwed in tight enough which may have been the issue.