Code P0171 Left bank too lean

[hpyman123]

Getting this code when I scan computer on my 97 Land Cruiser. Have replace front O2 sensor per dealer recommendation but am still getting the code. Anyone familiar with this??

[deekay140]

Po171 is system too lean, the most common cause would be a bad mass air flow sensor.

have seen a few coolant temp sensors bad also.

[hpyman123]

Thanks for the response. Anything else that could be the problem?

[OEMonkey]

deekay is right. if manifold vac and fuel pressure checks out ok, it's almost always the maf sensor.

[hpyman123]

Thanks for the help I appreciate it.

[raycwang]

Check my post on this forum on "P0171", I cure it by clean the MAF sensor, after spending money for new fuel filter, cleaning injector and new O2 sensor. It seems the dealer alway start with the most expansive part to replace instead of the cheapest cure.

[humanoid]

I'm betting 99.99% that it's the MAF sensor. Give it a good cleaning and reset the ECU and you will be !

[Smoke]

Are you using the K&N air filter?