Q: my car is slow to accelerate. i have a p0171 code. i replaced my o2 sensor but the code came back on. what else could it be?

asked by on

my car is slow to accelerate. i have a p0171 code. i replaced my o2 sensor but the code came back on. what else could it be?

My car has 230000 miles.
My car has an automatic transmission.

The code P0171 is a lean code indicating the O2 sensor is detecting the engine is running lean – that is, the air/fuel mixture is imbalanced. You may have a clogged fuel filter or a fuel pump that is not supplying enough fuel pressure. You will need to have the fuel pressure and volume checked with a fuel pressure gauge. You can try to replace the fuel filter to see if it helps first. Your best thing to do is to have a mechanic diagnose the problem and check the fuel pressures and filter. Also make sure your air filter is clean and the inlet air tube is not cracked or loose.

Check these items, and if you still need assistance, contact a professional mechanic. A certified mobile mechanic from YourMechanic can visit your home or office to inspect your vehicle’s acceleration issues.

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. my car is slow to accelerate. i have a p0171 code. i replaced my o2 sensor but the code came back on. what else could it be?

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: Brakes fade and pedal go to the floor

The brake pedal should stay up hard when you have the engine off. As long as you do not see any loss of fluid after system is bled out of any air in the system. You may need to have...

Q: Q: What could this be

Hi there. The squeaking sound you are hearing is most likely caused by the serpentine belt or the pulley's that drive the belt. In regards to routine maintenance on your Honda Civic, we have a great online tool that allows...

Q: My valve cover gasket is visible from outside after replacement i haven't fastened to proper torque yet. Should metals touch?

Hi Paco. It depends on what type of gasket you've used. An OEM replacement gasket for the 4-cylinder Toyota Corolla engine will fit snug under the valve cover after installation and wait 24-hours for the silicone to cure. If you...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.