Code P0171 Lean bank 1 unless premium gas

ERIC TOMLIN

MEMBER
2007 TOYOTA CAMRY
4 CYL
2WD
AUTOMATIC
90,711 MILES

I'm getting a p0171 check engine code (lean bank 1). Took the car to a mechanic. No leaks, replaced MAF sensor and both 02 sensors. Code came back. Code goes away when I use premium gas and come back as soon as I use regular again.

Sunday, January 20th, 2019 AT 1:20 PM

3 Replies

ASEMASTER6371

MECHANIC
52,797 POSTS

Good afternoon,

The code is an indication the car is running lean. This means there is not enough fuel and too much air.

Did you get any information from the guy that checked it? I would like to know the long term trims on the O2 sensors.

Possibilities below. One common item for this code is low fuel pressure. I would start there.

Roy

P0171
Descriptor
2Az-Fe Engine Control System
2Gr-Fe Engine Control System
Probable Causes
Air Fuel (A/F) Ratio Sensor 1
Air Fuel (A/F) Ratio Sensor Bank 1, 2 Sensor 1
Air Fuel (A/F) Ratio Sensor Heater Bank 1, 2 Sensor 1
Air Fuel (A/F) Ratio Sensor Heater Sensor 1
Air Fuel (A/F) Ratio Sensor Heater and EFI Relay Circuits
Air Fuel (A/F) Ratio Sensor Heater and Heater Relay Circuits
Air Fuel (A/F) Sensor Heater Relay
Air Fuel Ratio Sensor 1 Circuit Open or Short
Air Induction System
Engine Control Module (ECM)
Engine Coolant Temperature (ECT) Sensor
Engine Room Junction Block - Electronic Fuel Injection (EFI) Relay
Fuel Pressure
Gas Leakage From Exhaust System
Injector Blockage
Mass Air Flow (MAF) Meter
Open or Short In Air Fuel Ratio (A/F) Sensor Bank 1, 2 Sensor 1 Circuit
Positive Crankcase Emissions Valve (PCV) Hose Connections
Positive Crankcase Emissions Valve (PCV) Valve and Hose