Can a bad fuel pump cause a P0171 code?
Causes of the P0171 code may include: A faulty fuel pressure regulator. A weak fuel pump. A clogged fuel filter.
Can a vacuum leak cause P0171?
Sometimes the intake manifold gasket, throttle body gasket or even a vacuum line or hose will leak engine vacuum which will result in a P0171 code in the computer. Sometimes these leaks are hard to find.
How do you fix P0171 and P0174?
If your computer logged both P0171 and P0174 codes, concentrate on those components affecting all cylinders, like a MAF sensor, a clogged fuel filter, or issues with a fuel pressure regulator. Otherwise, concentrate on the side of the engine represented by your diagnostic trouble code.
What does the p0171 code for lean air mean?
The P0171 tells us that there is a lean air-fuel mixture, but it doesn’t tell us what could cause a lean fuel mixture. There are actually many different things that can cause a lean mixture; here are some of them. What repairs can fix the P0171 code?
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.
When does the front O2 sensor Register p0171?
P0171 is triggered when the front O2 sensors recognize a lean mixture. It can both be a short-term lean mixture or a long-term lean mixture. If it’s a short-term lean mixture the fuel mixture is often very lean. If it’s a long-term mixture, it can register the code because of a small notice of lean mixture over time.
What causes the code p0171 on 2002 Toyota Corolla?
Q: What could cause the code P0171 on 2002 Toyota Corolla? A: In the 2002 Corolla, the code P0171 is often caused by a bad or dirty mass airflow sensor or vacuum leaks. Your mechanic can check for vacuum leaks and test the mass airflow sensor with a scan tool.