Fuel Trim,Bank1 System too Lean

[tackleberry]

Hello everyone, my girlfriends 2001 leon cupra has had its engine light come on for the second time in 3 weeks. I ran it on vag com and got:
16555 P0171 Fuel Trim,Bank1 System too Lean
Now I've done some searching on here and narrowed it down to either that the maf or lambda probe is on the way out.
I know how to do logs of the MAF but how would i find out about the lamda probe?
Also how many grams should a standard leon cupra be seeing?

 

[m0rk]

About 140g/s really

could also be an air leak

 

[tackleberry]

An air leak or boost leak? if air where abouts should i be looking?

 

[m0rk]

both really.... as it's a pressurised system

 

[tackleberry]

with an air leak wouldn't i notice a performance difference or hear it leaking?

 

[tackleberry]

just done some logging: outside temp 26 C and maf never read above 90 g/s in 3, 4, 5 or 6th all the way to the readline in all gears. The car felt quite flat today i know it might be the temps but still. How would i do logs/tests to see if the lamda sensor is knackered with out buying/borrowing one. What methods have i got for finding boost/air leaks outside of a rolling road?

 

[Saul]

i think you have to check the voltage output from the sensor to check its operation, not too sure on this, would recommend you search for lamda or ask around to anyone who has had the same problem (cordobabrendy i know had a lamda problem)

as you say, sounds like MAF or lamda tho

as for boost leak, check the duty cycle on the N75 if its 100% for any length of time at full boost could be a leak

PS dont double post, its a pita to answer to

 

[tackleberry]

cheers for the info (sorry for double posting) the missis has gone out for now so when i can i'll do some n75 logs and report back

 

[badunseat]

Can anyone help?

I have a problem with Leon Cupra 1.8T 20V

First abs/esp light kept coming on, then engine management light came on at same time, then both kept coming on seperately, got a mate who hooked up to a fault finder and got error code: P0171 System Too Lean, Bank1 had a brief look on tinternet but cant' really pin it down to one thing, can anyone help don't want to get robbed by a dealer, who tells me something it ain't and charges arm and leg.
Took MAF off and cleaned out because was loose, but don't know what to try next????:

Cheers

Badunseat