How do I fix bank 2 running lean?
First and foremost, start by parking your vehicle on a flat ground and use an emergency brake set.
- Test For Vacuum Leaks.
- Test For Exhaust Leaks.
- Test The Service Mass Airflow Sensor MAF.
- Test The Oxygen Sensor.
- Test The Sparkplug.
- Test The Air Intake Boot Replacement.
What causes fuel system too lean?
The lean condition can be caused by a vacuum leak, which introduces more air into the air-fuel mixture, or by a weak fuel system, which does not input enough fuel into the air-fuel mixture.
What does code p0171-system too lean mean?
Code P0171 – System Too Lean: Symptoms, causes, common problems, diagnostic. The OBDII trouble code P0171 – System Too Lean (Bank 1) means that the engine air-fuel mixture is too lean, or there is too much air and too little fuel.
What does the code p0171 mean on a Toyota 4Runner?
4Runner P0171 Code Defined. P0171 is an OBDII trouble code. The code technically stands for: Fuel Trim System Lean Bank 1. The code is thrown when the oxygen sensors detect that there’s not enough oxygen in the exhaust system. This is commonly referred to as a “lean” condition.
What causes the p0171 code on a Ford TSB?
Another Ford TSB for a number of late 90-s Ford vehicles describes a problem with MAF sensor contamination where both codes, P0171 and P0174 would appear together. Problems with the mass air flow (MAF) sensor causing the code P0171 are fairly common in many vehicles.
What does p0171 mean on a bank 2 sensor?
Quite often P0171 is triggered in tandem with P0174, which comes on when the Bank 2 sensor detects too much oxygen in the exhaust. Oftentimes, a P0171 means that your Toyota is having trouble with a dirty or faulty mass air flow (MAF) sensor, or a vacuum leak downstream of the MAF sensor (perhaps in the PCV line or in the valve itself).