Q: Car is jerking back and forth. P0171 and P0172 codes are on.

asked by on

Car runs like normal but after a while will begin to struggle jerk back and forth and won't accelerate if I hit the gas pedal then will go and shut off on me and won't turn back on until after a couple of minutes. Car does it every now and then at random times shows the check engine light and shows both codes p0171 and p0172.

My car has 170000 miles.
My car has an automatic transmission.

Hello. These symptoms suggest something is causing big swings in the fuel mixture when this occurs - quite possibly the O2 sensors (pre-catalytic converter - 2 of them). P0171 is a "lean mix" warning, and P0172 is a "rich mix" warning. They may be able to keep the engine within boundaries most of the time, but not all. If the O2 sensors on your Impala are the originals, they are certainly well-used at this point, and should be replaced. I would recommend having an oxygen sensor replacement for the two pre-catalytic converter sensors. If you’d like to have this done, a certified professional from YourMechanic can perform these services at your home or office.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Car is jerking back and forth. P0171 and P0172 codes are on.

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

Get a quote

What others are asking

Q: Q: How I replace fuel filter

The fuel filter for your car is in the fuel tank. If you want to replace it, you will need to replace the fuel pump. It isn't regularly serviceable item anymore. As for the codes, the P0172 indicates there is...

Q: Stalling dying when stopped

That sounds like a frustrating issue for your 2005 Kia Spectra5! I'm wondering how it runs when you're going down the road and not trying to idle at a stop. If it drives okay, but won't idle, then that's a...

Q: Is a 2011 Chevy Impala equipped with magnasteer?

Magnasteer was not an option on the 2011 Impala so what you are looking at is an irrelevant catalog entry (an error in the parts catalog). However, several different rack and pinion units were installed on the 2011 Impala and...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...