How Is P0171 Diagnosed?

How does a mechanic diagnose the P0171 code? Assuming that no other trouble codes exist, a mechanic may diagnose the P0171 code by

checking the engine for vacuum leaks with a vacuum gauge and checking the fuel pressure with a fuel pressure gauge

.

How do I fix P0171 too lean?

1. Replacing the fuel pump.
2. Replacing the fuel filter.
3. Replacing the fuel pressure regulator.
4. Replacing the powertrain control module.
5. Replacing one or more injectors.
6. Replacing one or more oxygen sensors.
7. Replacing the mass air flow sensor.
8. Repairing a vacuum leak.

What causes P0171?

A plugged Fuel Filter or poorly functioning Fuel Pump

can set the P0171 code. The computer hears (accurately) from the Oxygen Sensor that the Fuel Mixture is too lean so the computer keeps increasing the amount of fuel being delivered into the combustion chambers.

Can a bad O2 sensor cause a P0171?

You probably know that the answer the questions is — no! A P0171 or P0174 lean code with an O2 sensor reading lean all the time mean — well, several things. The real problem

may not be a bad O2 sensor

, but possibly be an engine vacuum leak, low fuel pressure or dirty fuel injectors that are causing the engine run lean.

Can a dirty air filter cause a P0171 code?

If the filter is clogged or excessively dirty, this is enough to impede or restrict the air flow, hence resulting in a lean running condition. Besides a dirty air filter, the P0171 code can also

be blamed on a dirty or faulty MAF sensor and a clogged fuel filter

.

What does P0171 System Too Lean Bank #1 mean?

The P0171 code means that, on the first bank of the engine, the

fuel system is running weak or a vacuum leak exists near this side of the engine

. A lean condition occurs when the engine either receives too little fuel or too much air.

How much does it cost to fix P0171?

Perhaps your P0171 OBD-II Trouble Code: System Too Lean Bank 1 trouble code is appearing because it is due to you needing to replace your fuel injector/injectors. Generally, a fuel injector replacement cost will

between $800 and $1,450

for a full replacement.

Is it OK to drive with P0171 code?

It is okay to drive a vehicle with P0171

for a short period of time

, but driving with this code for an extended period of time can overheat the engine and cause internal engine damage.

Can P0171 cause misfire?

What are the symptoms for a P0171 code? Generally, a lean code will cause the engine to run poorly, which the driver will notice as a high idle, a

misfire

, a lack of power, or even engine stalling, and this may happen before the check engine light has turned on.

How do I reset my P0171 code?

1. Step 1: Purchase a OBD 2 Bluetooth Scanner. …
2. Step 2: Insert the Scanner Into the OBD 2 Port of Your Car. …
3. Step 3: Run a Diagnostic Scan. …
4. Step 4: P0171. …
5. Step 5: Removing the Mass Air Flow Sensor. …
6. Step 6: The MAF Sensor. …
7. Step 7: Clean the Sensor. …
8. Step 8: Clear the Code.

What does it mean when bank 1 system too lean?

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. Driving a car with the code P0171 can cause more damage to the engine over time, as when the engine runs lean, the combustion temperature is higher.

What side of the engine is Bank 1?

Bank 1 and bank 2 simply refer to either side of the engine. Check your owner's manual or a service manual for a positive location of bank 1 and bank 2. Most commonly, bank 1 houses

the front most cylinder on

the engine cylinder 1, and bank 2 is the opposite side of the engine.

Can a dirty air filter cause a P0101 code?

In vehicles with an oil-soaked aftermarket air filter,

oil from the air filter can contaminate the MAF sensor element

, causing the code P0101 or other MAF-related codes. In some Volvo cars, the code P0101 could be caused by a dirty throttle body or vacuum leaks in the PCV system (e.g. vacuum line to the oil separator).

What are the signs of a bad air filter?

• Air Filter Appears Dirty. …
• Decreasing Gas Mileage. …
• Your Engine Misses or Misfires. …
• Strange Engine Noises. …
• Check Engine Light Comes On. …
• Reduction in Horsepower. …
• Flames or Black Smoke from Exhaust Pipe. …
• Strong Fuel Smell.

Can a dirty air filter cause car to shake?

Engine Problems

There are a few parts within a vehicle's engine that could cause a car to shake if they malfunction. These include the spark plugs and engine air filter. … A dirty or clogged engine air filter

can starve the engine of oxygen and/or fuel that it needs to run properly

.