P1071 Error Code

[westerner]

Hey guys,

I've searched for this and haven't come up with much other than the same error code for a bunch of other vehicles, and a bunch of different responses. My Tacoma is a 2000 PreRunner, 3.4 liter engine.

The exact code I get it is:

P1071
bank 1 system too lean

Anyone know what this could be?

Thanks in advance for any and all help! Sorry if this has already been posted and I missed it in the search.

[Brian R.]

It is likely that you misread it and it is P0171. That is a common code for that engine

System too Lean (Bank 1)

Possible Problems
When the air fuel ratio feedback is stable after engine warming up, the fuel trim is considerably in error on the LEAN side (2 trip detection logic)

Air intake hose loose
Fuel line pressure low (may be from running out of gas)
Injector blockage
HO2 sensor malfuction
MAF meter or MAP sensor malfunction
Engine coolant temperature sensor malfunction

Clean MAF meter with electronic circuit cleaner or replace<= most likely
Fix vacuum/intake leak downstream of MAF meter
Inspect fuel lines for cracks, leaks, or pinches
Replace fuel filter
Check fuel pressure at the fuel rail
Check output of HO2 sensor
Check injector performance
Check ECT sensor
Check PCV valve and hose fittings for tightness

Most likely problem is dirty or contaminated MAF sensor.