Skip the auto shop - Our mechanics make house calls

Q: Check engine light coming on

asked by on

My car's check engine light has been coming on. It has given me this code twice: P0171 (Bank 1 too lean). The first time it happened, I had the light turned off to see if it would come back. The first time it the light came on, I chalked it up to being the cold and dense air outside and the vehicle not being able to catch up. So, the light stayed off for about a month. Then, it came back on after another really cold day, and it gave the same code. My car is idling a bit lower than usual, and has for awhile even before the check engine light came on. I've noticed no major difference in performance or power in my car. Autozone gave me a print out of possible solutions to the problem, the easiest being replacing the O2 sensor on the manifold. Any advice or other ideas?

Cold weather causes plastic and rubber components to contract. The intake manifold on my truck would expand and contract every winter, setting P0171 and P0174 lean codes. Then finally, this past winter, the manifold cracked. My guess is that you have a vacuum leak somewhere due to shrinkage from the cold weather. The source of the leak could be anything from a vacuum hose to an intake manifold, like my truck. A trained professional will be able to pinpoint the leak using a smoke machine. I suggest you contact a trained professional to diagnose your Check Engine Light code firsthand, they will be able to follow through with the necessary repair procedures in order to fix your vehicle.

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

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: Throttle position sensor light on

For many vehicles, regardless of manufacturer, there is the need to do a "re-learn" sequence (after replacing the TPS or a battery) so the TPS and transmission will work smoothly. You may have to drive the vehicle for a bit...

Q: Heat working, but AC doesn't

The AC on this car is known to have one or more of many possible failures from the compressor, from lines leaking, to control module problems. I recommend that you have a mechanic, like the ones from YourMechanic, do a...

Q: I think it has a blown head gasket I was wondering for now if Bar's Leak Block seal and head gasket repair would help til I could

Hey there, thanks for writing in about your 2001 Chevrolet Impala. The stop leak is only temporary and may not even work the first time. If you use too much or not as directed it may block the radiator and...

Related articles

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...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
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...