Skip the auto shop - Our mechanics make house calls

Q: P0171

asked by on

I had a p0325 and p0171. I fixed the knock sensor but the lean bank 1 is killing me. I have replaced the MAF, PCV, FRONT O2 SENSOR, found one vac leak and replaced hose. STILL HAS P0171, What am I missing? HELP!!!!!!

My car has 188000 miles.
My car has an automatic transmission.

A: The code P0171 is due to the left bank of t...

The code P0171 is due to the left bank of the engine running lean and has reached the rich limit for the ECM. Try to have the injectors cleaned and run only high quality fuel that has cleaning additives. This should clean out the injectors and combustion chambers and clear the code. If you need help having this done, a certified technician from YourMechanic can inspect the code in person to determine the appropriate actions.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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: No rear lights

Hello. Depending on how they wired the trailer lights up, the wiring harness might need to be replaced. Some trailer lighting comes as an inline harness that plugs into the existing vehicle's wiring. This is the normally the best way...

Q: Getting knocking sound when engine is idling from the floor front and side of the engine

Hello, thank you for writing in. The knocking is going to sound worse at idle because the number of combustion cycles happening is less than when you are accelerating or maintaining a higher RPM. With that being said, engine knock...

Q: Service light soon turned on today

Your check engine light may come on for many different reasons such as a faulty mass air flow sensor, a faulty O2 sensor, a bad catalytic converter, bad spark plugs or wires and many other reasons. Since you just had...

Related articles

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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...