Q: I have this code, P0171 I replaced my air filter, MAF sensor and PCV, but the code keeps coming back after erasing it.

asked by on July 11, 2017

P0171 keeps coming back replaced my air filter, MAF sensor, and PCV . I really don't know what else to do. Please help me solve this annoying check engine light.

My car has 13000 miles.
My car has an automatic transmission.

Check Engine Light is on Inspection $79.99 - $99.99 Get a Quote

This code indicates that the fuel system on bank one is weak or that a vacuum leak exists on that side of the engine. Bank one of the engine is running lean which means that either too little fuel or too much air is being introduced into the cylinders. I would recommend having your vehicle looked at with a check engine light inspection to determine the exact cause of this issue. Consider YourMechanic as this service can be completed from your home or office.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $65/hr

What others are asking

Its misfiring on cyl 5 and has a code for an o2 sensor.

Diagnostic Trouble Code P0305 means that Cylinder No. 5 is misfiring but the causes of that can be very varied. Check the plug, secondary wire, and distributor cap. The fuel injector to the cylinder could simply be faulty or there...

Car sputters when 1st press on gas

You should have the computer tested and fuel pressure tested to help isolate the problem. You may have a fuel or ignition related problem that needs to be isolated first. The igniter or coil may be not supplying enough spark...

Issues with coolant, afraid of blown head gasket.

If the coolant is not leaking externally then it is leaking internally into the engine cylinder. I suggest looking inside the oil cap or on dipstick to see if the oil is contaminated with coolant. The oil would look milky...

Sugar in the gas tank

The first thing that has to happen is the fuel tank has to come out of the car and be thoroughly cleaned. The fuel pump, which lives inside the tank will need to be replaced. Your car may have an...

What side is my starter on a 2006 nissan pathfinder

Hello, thank you for writing in. The starter is tucked up behind the oil pan towards the right side of the vehicle. The right side is also known as the passenger side of the vehicle. There should be two mounting...

Flapping sounds at average speed, steering wheel shakes

This type of situation is caused by a rotational imbalance or load variation on the tires. My recommendation would be to have the tire road force balanced and matched for least vibration. This type of balance will put the...

Mechanic told me that the P1125 cod meant that one of 2 transmission sensors had gone bad on my 2002 Toyota Echo. He does not know

After checking the manual for the code P1125 I have found that this code is not listed for this vehicle. Can you verify the code and the vehicle information so we can help you better. i would not recommend not...

Engine/battery light on

If the Engine and Battery Light have come on, then you probably have two separate problems. The Battery Light may indicate that the system's voltage may have dropped too low, which may be indicative of even more problems, such as...

2005 Toyota Prius won't turn off

The symptoms you describe for your Toyota Prius lead me to believe you have a bad ground in your electrical system. A bad ground connection can create all kinds of electrical problems, as it prevents adequate voltage from reaching the...

Related articles

The Best Used Cars to Buy If You’re a Caterer
If If you are in the catering business, you need a reliable vehicle that will provide you with what you need to transport your food, linens, and other supplies. Generally speaking, you're better off buying gently used, because you will...
Toyota Certified Pre-Owned (CPO) Car Program
If If you have been shopping for a used Toyota vehicle, you may want to check out cars under their certified pre-owned program. Many manufacturers have a certified pre-owned (CPO) program, and each one is set up differently. Read on...
A Buyer’s Guide to the 2011 Toyota Land Cruiser
This This multi-tasking full-size SUV offers all the versatility of a traditional mini-van with the amenities and comfort level of a high-end sedan. Add in the 4WD that allows you to chew up rough terrain if desired (or necessary) and...