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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?

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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.

A: The code P0171 is a lean code indicating th...

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.

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