k-jones-087

i have 01 bug wrx with p0171 i cant seem to fix,put rear 02 sensor and front air/feul sensor on graph and front sensor dosent switch at all at idle, if im driving it only switchs slowly if i throttle off or on. seems to stay around 1v, surely it should be switching alot and fast????

rob84

iTrader: (5)

P0171 - System to Lean (Bank 1).

Usually low fuel pressure or intake system leaks cause this code to be triggered.

Can you read what the % of compensation there is on that sensor ??

k-jones-087

thanks for reply,checked fuel pressure today, was just over 2.5bar, not great so think this is my fault. it has walbro pump in it already according to last owner but im gonna fit new one anyway and will post afterwards to let ya know

rob84

iTrader: (5)

2.5bar isnt too bad for idle speed, what did it read if you reved the engine up

k-jones-087

the same,the needle barely moved,it tried to go for 3bar at one stage but stayed at around 2.5 no matter how high i reved it, and i noticed recently the pump is getting very noisey,sometimes changing pitch,